diff --git a/pyproject.toml b/pyproject.toml
index 0c4e31e..08201db 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -77,6 +77,9 @@ select = [
     "B", # flake8-bugbear
     "SIM", # flake8-simplify
 ]
+ignore = [
+    "E501",
+]
 
 [tool.pytest.ini_options]
 testpaths = [
@@ -85,3 +88,6 @@ testpaths = [
 addopts = [
     "--import-mode=importlib",
 ]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+]
diff --git a/src/onc/modules/_DataProductFile.py b/src/onc/modules/_DataProductFile.py
index b3d1e23..16b11fa 100644
--- a/src/onc/modules/_DataProductFile.py
+++ b/src/onc/modules/_DataProductFile.py
@@ -15,11 +15,23 @@ def __init__(self, max_retries):
 
 class _DataProductFile:
     """
-    Donwloads a single data product file
+    Downloads a single data product file
     Is able to poll and wait if required
     """
 
-    def __init__(self, dpRunId: int, index: str, baseUrl: str, token: str):
+    def __init__(
+        self,
+        dpRunId: int,
+        index: str,
+        baseUrl: str,
+        token: str,
+        verbosity: str = "INFO",
+    ):
+        self.verbosity = verbosity
+        # Use child logger 'onc.poll' consistent with _PollLog
+        from ._Messages import setup_logger
+
+        self._log = setup_logger("onc.poll", verbosity)
         self._retries = 0
         self._status = 202
         self._downloaded = False
@@ -50,7 +62,7 @@ def download(
         Can poll, wait and retry if the file is not ready to download
         Return the file information
         """
-        log = _PollLog(True)
+        log = _PollLog(self.verbosity)
         self._status = 202
         while self._status == 202:
             # Run timed request
@@ -74,9 +86,9 @@ def download(
                         response, outPath, filename, overwrite
                     )
                 except FileExistsError:
-                    if self._retries > 1:
-                        print("")
-                    print(f'   Skipping "{self._filePath}": File already exists.')
+                    self._log.info(
+                        f'   Skipping "{self._filePath}": File already exists.'
+                    )
                     self._status = 777
 
             elif self._status == 202:  # Still processing, wait and retry
@@ -84,10 +96,9 @@ def download(
                 sleep(pollPeriod)
 
             elif self._status == 204:  # No data found
-                print("   No data found.")
+                self._log.info("   No data found.")
 
             elif self._status == 404:  # Index too high, no more files to download
-                log.printNewLine()
                 pass
 
             elif self._status == 410:  # Status 410: gone (file deleted from FTP)
@@ -98,7 +109,8 @@ def download(
                     stacklevel=2,
                 )
             else:
-                raise requests.HTTPError(_createErrorMessage(response))
+                self._log.error(_createErrorMessage(response))
+                response.raise_for_status()
 
         return self._status
 
diff --git a/src/onc/modules/_Messages.py b/src/onc/modules/_Messages.py
new file mode 100644
index 0000000..821625c
--- /dev/null
+++ b/src/onc/modules/_Messages.py
@@ -0,0 +1,139 @@
+import logging
+import re
+import time
+
+import requests
+
+REQ_MSG = "Requested: {}"  # get request url
+RESPONSE_TIME_MSG = "Response received in {} seconds."  # requests.elapsed value.
+RESPONSE_MSG = "HTTP Response: {} ({})"  # Brief description, status code
+MULTIPAGE_MSG = (
+    "The requested data quantity is greater than the "
+    "supplied row limit and will be downloaded over multiple requests."
+)
+
+
+LEVEL_MAP = {
+    "CRITICAL": logging.CRITICAL,
+    "ERROR": logging.ERROR,
+    "WARNING": logging.WARNING,
+    "INFO": logging.INFO,
+    "DEBUG": logging.DEBUG,
+}
+
+
+class OnclibFormatter(logging.Formatter):
+    """
+    Custom formatter that removes prefix for INFO level logs.
+    """
+
+    def format(self, record):
+        if record.levelno == logging.INFO:
+            return record.getMessage()
+        return super().format(record)
+
+
+def setup_logger(logger_name: str = "onc", level: int | str = "INFO") -> logging.Logger:
+    """
+    Set up a logger object for displaying verbose messages to console.
+
+    Parameters
+    ----------
+    logger_name : str, optional
+        The unique logger name to use. Can be shared between modules.
+    level : int or str, optional
+        The logging level to use. Default is 'INFO'.
+
+    Returns
+    -------
+    logging.Logger
+        The configured logging.Logger object.
+    """
+
+    # Ensure level is a valid logging level integer
+    if isinstance(level, str):
+        level = LEVEL_MAP.get(level.upper(), logging.INFO)
+
+    logger = logging.getLogger(logger_name)
+    logger.propagate = False
+
+    # Apply level to the logger itself
+    logger.setLevel(level)
+
+    if not logger.handlers:
+        console = logging.StreamHandler()
+        console.setLevel(level)
+
+        # Set the logging format.
+        dtfmt = "%Y-%m-%dT%H:%M:%S"
+        strfmt = (
+            "%(asctime)s.%(msecs)03dZ | %(name)-12s | %(levelname)-8s | %(message)s"
+        )
+        fmt = OnclibFormatter(strfmt, datefmt=dtfmt)
+        fmt.converter = time.gmtime
+
+        console.setFormatter(fmt)
+        logger.addHandler(console)
+    else:
+        # If handlers exist, ensure they have the correct level
+        for handler in logger.handlers:
+            handler.setLevel(level)
+
+    return logger
+
+
+def scrub_token(input: str) -> str:
+    """
+    Replace a token in a query URL or other string with the string 'REDACTED'
+    so that users don't accidentally commit their tokens to public repositories
+    if ONC Info/Warnings are too verbose.
+
+    Parameters
+    ----------
+    input : str
+        An Oceans 3.0 API URL or string with a token query parameter.
+
+    Returns
+    -------
+    str
+        A scrubbed url.
+    """
+    return re.sub(r"([?&]token=)[a-f0-9-]{36}", r"\1REDACTED", input)
+
+
+def build_error_message(response: requests.Response, redact_token: bool) -> str:
+    """
+    Build an error message from a requests.Response object.
+
+    Parameters
+    ----------
+    response : requests.Response
+        A requests.Response object.
+    redact_token : bool
+        If true, redact tokens before returning an error message.
+
+    Returns
+    -------
+    str
+        An error message.
+    """
+    payload = response.json()
+    message = payload.get("message")
+
+    if "errors" in payload:
+        errors = payload["errors"]
+        error_messages = []
+        for error in errors:
+            emsg = (
+                f"(API Error Code {error['errorCode']}) "
+                f"{error['errorMessage']} for query parameter(s) "
+                f"'{error['parameter']}'."
+            )
+            error_messages.append(emsg)
+        error_message = "\n".join(error_messages)
+    else:
+        error_message = None
+    msg = "\n".join([m for m in (message, error_message) if m is not None])
+    if redact_token is True and "token=" in msg:
+        msg = scrub_token(msg)
+    return msg
diff --git a/src/onc/modules/_MultiPage.py b/src/onc/modules/_MultiPage.py
index 6369773..af458de 100644
--- a/src/onc/modules/_MultiPage.py
+++ b/src/onc/modules/_MultiPage.py
@@ -4,7 +4,9 @@
 from time import time
 
 import dateutil.parser
-import humanize
+from onc.modules._Messages import (
+    setup_logger,
+)
 
 from ._util import _formatDuration
 
@@ -14,12 +16,25 @@ class _MultiPage:
     def __init__(self, parent: object):
         self.parent = weakref.ref(parent)
         self.result = None
+        self._log = setup_logger("onc.multi", self._config("verbosity") or "INFO")
+
+    def _config(self, key):
+        p = self.parent()
+        if p is None:
+            return None
+        if hasattr(p, "_config"):
+            return p._config(key)
+        return getattr(p, key, None)
 
     def getAllPages(self, service: str, url: str, filters: dict):
         """
         Requests all pages from the service, with the url and filters
         Multiple pages will be downloaded until completed
-        @return: Service response with concatenated data for all pages obtained
+
+        Returns
+        -------
+        dict
+            Service response with concatenated data for all pages obtained.
         """
         # pop archivefiles extension
         extension = None
@@ -30,48 +45,54 @@ def getAllPages(self, service: str, url: str, filters: dict):
         # download first page
         start = time()
         response, responseTime = self._doPageRequest(url, filters, service, extension)
-        rNext = response["next"]
-
-        if rNext is not None:
-            print(
-                "Data quantity is greater than the row limit and",
-                "will be downloaded in multiple pages.",
-            )
-
-            pageCount = 1
-            pageEstimate = self._estimatePages(response, service)
-            if pageEstimate > 0:
-                # Exclude the first page when calculating the time estimation
-                timeEstimate = _formatDuration((pageEstimate - 1) * responseTime)
-                print(
-                    f"Downloading time for the first page: {humanize.naturaldelta(responseTime)}"  # noqa: E501
-                )
-                print(f"Estimated approx. {pageEstimate} pages in total.")
-                print(
-                    f"Estimated approx. {timeEstimate} to complete for the rest of the pages."  # noqa: E501
-                )
 
-            # keep downloading pages until next is None
-            print("")
-            while rNext is not None:
-                pageCount += 1
-                rowCount = self._rowCount(response, service)
+        if isinstance(response, dict):
+            rNext = response["next"]
 
-                print(f"   ({rowCount} samples) Downloading page {pageCount}...")
-                nextResponse, nextTime = self._doPageRequest(
-                    url, rNext["parameters"], service, extension
+            if rNext is not None:
+                self._log.info(
+                    "The requested data quantity is greater than the supplied "
+                    "row limit and will be downloaded over multiple requests."
                 )
-                rNext = nextResponse["next"]
-
-                # concatenate new data obtained
-                self._catenateData(response, nextResponse, service)
 
-            totalTime = _formatDuration(time() - start)
-            print(
-                f"   ({self._rowCount(response, service):d} samples)"
-                f" Completed in {totalTime}."
-            )
-            response["next"] = None
+                pageCount = 1
+                pageEstimate = self._estimatePages(response, service)
+                if pageEstimate > 0:
+                    # Exclude the first page when calculating the time estimation
+                    timeEstimate = _formatDuration((pageEstimate - 1) * responseTime)
+                    self._log.info(
+                        f"Download time for page {pageCount}: {round(responseTime, 2)} seconds"
+                    )
+                    self._log.info(
+                        f"Est. number of pages remaining for download: {pageEstimate - 1}"
+                    )
+                    self._log.info(
+                        f"Est. number of seconds to download remaining data: {timeEstimate}"
+                    )
+
+                # keep downloading pages until next is None
+                while rNext is not None:
+                    pageCount += 1
+                    rowCount = self._rowCount(response, service)
+
+                    self._log.info(
+                        f"   Submitting request for page {pageCount} ({rowCount} samples)..."
+                    )
+
+                    nextResponse, nextTime = self._doPageRequest(
+                        url, rNext["parameters"], service, extension
+                    )
+                    rNext = nextResponse["next"]
+
+                    # concatenate new data obtained
+                    self._catenateData(response, nextResponse, service)
+
+                totalTime = _formatDuration(time() - start)
+
+                self._log.info(
+                    f"   Downloaded {self._rowCount(response, service):d} total samples in {totalTime}."
+                )
+                response["next"] = None
 
         return response
 
@@ -81,8 +102,22 @@ def _doPageRequest(
         """
         Wraps the _doRequest method
         Performs additional processing of the response for certain services
-        @param extension: Only provide for archivefiles filtering
-        Returns a tuple (jsonResponse, duration)
+
+        Parameters
+        ----------
+        url : str
+            API endpoint URL.
+        filters : dict
+            Filters for the request.
+        service : str
+            Name of the service (e.g. archivefile).
+        extension : str, optional
+            Only provide for archivefiles filtering.
+
+        Returns
+        -------
+        tuple
+            (jsonResponse, duration)
         """
         if service.startswith("archivefile"):
             response, duration = self.parent()._doRequest(url, filters, getTime=True)
diff --git a/src/onc/modules/_OncArchive.py b/src/onc/modules/_OncArchive.py
index 9129a99..759e061 100644
--- a/src/onc/modules/_OncArchive.py
+++ b/src/onc/modules/_OncArchive.py
@@ -6,7 +6,7 @@
 
 from ._MultiPage import _MultiPage
 from ._OncService import _OncService
-from ._util import _createErrorMessage, _formatDuration, saveAsFile
+from ._util import _formatDuration, saveAsFile
 
 
 class _OncArchive(_OncService):
@@ -73,8 +73,10 @@ def downloadArchivefile(self, filename: str = "", overwrite: bool = False):
             size, downloadTime = saveAsFile(response, outPath, filename, overwrite)
 
         else:
-            msg = _createErrorMessage(response)
-            raise requests.HTTPError(msg)
+            from ._Messages import build_error_message
+
+            self._log.error(build_error_message(response, self._config("redact_token")))
+            response.raise_for_status()
 
         # Prepare a readable status
         txtStatus = "error"
@@ -109,7 +111,7 @@ def downloadDirectArchivefile(
         dataRows = self.getArchivefile(filters, allPages)
 
         n = len(dataRows["files"])
-        print(f"Obtained a list of {n} files to download.")
+        self._log.info(f"Obtained a list of {n} files to download.")
 
         # Download the files obtained
         tries = 1
@@ -124,7 +126,7 @@ def downloadDirectArchivefile(
             fileExists = os.path.exists(filePath)
 
             if not fileExists or os.path.getsize(filePath) == 0 or overwrite:
-                print(f'   ({tries} of {n}) Downloading file: "{filename}"')
+                self._log.info(f'   ({tries} of {n}) Downloading file: "{filename}"')
                 downInfo = self.downloadArchivefile(filename, overwrite)
                 size += downInfo["size"]
                 time += downInfo["downloadTime"]
@@ -132,7 +134,7 @@ def downloadDirectArchivefile(
                 successes += 1
                 tries += 1
             else:
-                print(f'   Skipping "{filename}": File already exists.')
+                self._log.info(f'   Skipping "{filename}": File already exists.')
                 downInfo = {
                     "url": self.getArchivefileUrl(filename),
                     "status": "skipped",
@@ -142,8 +144,8 @@ def downloadDirectArchivefile(
                 }
                 downInfos.append(downInfo)
 
-        print(f"{successes} files ({humanize.naturalsize(size)}) downloaded")
-        print(f"Total Download Time: {_formatDuration(time)}")
+        self._log.info(f"{successes} files ({humanize.naturalsize(size)}) downloaded")
+        self._log.info(f"Total Download Time: {_formatDuration(time)}")
 
         return {
             "downloadResults": downInfos,
diff --git a/src/onc/modules/_OncDelivery.py b/src/onc/modules/_OncDelivery.py
index 616ce24..3889b94 100644
--- a/src/onc/modules/_OncDelivery.py
+++ b/src/onc/modules/_OncDelivery.py
@@ -8,7 +8,7 @@
 from ._DataProductFile import _DataProductFile
 from ._OncService import _OncService
 from ._PollLog import _PollLog
-from ._util import _createErrorMessage, _formatSize
+from ._util import _formatSize
 
 
 class _OncDelivery(_OncService):
@@ -56,7 +56,6 @@ def orderDataProduct(
                     )
                 )
 
-            print("")
             self._printProductOrderStats(fileList, runData)
 
         return self._formatResult(fileList, runData)
@@ -88,9 +87,9 @@ def runDataProduct(self, dpRequestId: int, waitComplete: bool):
         Return a dictionary with information of the run process.
         """
         status = ""
-        log = _PollLog(True)
-        print(
-            f"To cancel the running data product, run 'onc.cancelDataProduct({dpRequestId})'"  # noqa: E501
+        log = _PollLog(self._config("verbosity"))
+        self._log.info(
+            f"To cancel the running data product, run 'onc.cancelDataProduct({dpRequestId})'"
         )
         url = f"{self._config('baseUrl')}api/dataProductDelivery/run"
         runResult = {"runIds": [], "fileCount": 0, "runTime": 0, "requestCount": 0}
@@ -111,7 +110,12 @@ def runDataProduct(self, dpRequestId: int, waitComplete: bool):
             if response.ok:
                 data = response.json()
             else:
-                raise requests.HTTPError(_createErrorMessage(response))
+                from ._Messages import build_error_message
+
+                self._log.error(
+                    build_error_message(response, self._config("redact_token"))
+                )
+                response.raise_for_status()
 
             if waitComplete:
                 status = data[0]["status"]
@@ -128,10 +132,6 @@ def runDataProduct(self, dpRequestId: int, waitComplete: bool):
         runResult["fileCount"] = data[0]["fileCount"]
         runResult["runTime"] = time() - start
 
-        # print a new line after the process finishes
-        if waitComplete:
-            print("")
-
         # gather a list of runIds
         for run in data:
             runResult["runIds"].append(run["dpRunId"])
@@ -192,9 +192,11 @@ def _downloadProductFiles(
         # keep increasing index until fileCount or until we get 404
         doLoop = True
         timeout = self._config("timeout")
-        print(f"\nDownloading data product files with runId {runId}...")
+        self._log.info(f"Downloading data product files with runId {runId}...")
 
-        dpf = _DataProductFile(runId, str(index), baseUrl, token)
+        dpf = _DataProductFile(
+            runId, str(index), baseUrl, token, self._config("verbosity")
+        )
 
         # loop thorugh file indexes
         while doLoop:
@@ -211,7 +213,9 @@ def _downloadProductFiles(
                 # file was downloaded (200), or skipped before downloading (777)
                 fileList.append(dpf.getInfo())
                 index += 1
-                dpf = _DataProductFile(runId, str(index), baseUrl, token)
+                dpf = _DataProductFile(
+                    runId, str(index), baseUrl, token, self._config("verbosity")
+                )
 
             elif status != 202 or (fileCount > 0 and index >= fileCount):
                 # no more files to download
@@ -219,7 +223,9 @@ def _downloadProductFiles(
 
         # get metadata if required
         if getMetadata:
-            dpf = _DataProductFile(runId, "meta", baseUrl, token)
+            dpf = _DataProductFile(
+                runId, "meta", baseUrl, token, self._config("verbosity")
+            )
             try:
                 status = dpf.download(
                     timeout,
@@ -248,8 +254,8 @@ def _infoForProductFiles(self, dpRunId: int, fileCount: int, getMetadata: bool):
         Returned rows will have the same structure as those returned by
         _DataProductFile.getInfo().
         """
-        print(
-            f"\nObtaining download information for data product files with runId {dpRunId}..."  # noqa: E501
+        self._log.info(
+            f"Obtaining download information for data product files with runId {dpRunId}..."
         )
 
         # If we don't know the fileCount, get it from the server (takes longer)
@@ -268,6 +274,7 @@ def _infoForProductFiles(self, dpRunId: int, fileCount: int, getMetadata: bool):
                 index=str(index),
                 baseUrl=self._config("baseUrl"),
                 token=self._config("token"),
+                verbosity=self._config("verbosity"),
             )
             dpf.setComplete()
             fileList.append(dpf.getInfo())
@@ -304,7 +311,7 @@ def _countFilesInProduct(self, runId: int):
                 filters["index"] += 1
                 n += 1
 
-        print(f"   {n} files available for download")
+        self._log.info(f"   {n} files available for download")
         return n
 
     def _printProductRequest(self, response):
@@ -315,19 +322,19 @@ def _printProductRequest(self, response):
         product source (archive or generated on the fly).
         """
         isGenerated = "estimatedFileSize" in response
-        print(f"Request Id: {response['dpRequestId']}")
+        self._log.info(f"Request Id: {response['dpRequestId']}")
 
         if isGenerated:
             size = response["estimatedFileSize"]  # API returns it as a formatted string
-            print(f"Estimated File Size: {size}")
+            self._log.info(f"Estimated File Size: {size}")
             if "estimatedProcessingTime" in response:
-                print(
+                self._log.info(
                     f"Estimated Processing Time: {response['estimatedProcessingTime']}"
                 )
         else:
             size = _formatSize(response["fileSize"])
-            print(f"File Size: {size}")
-            print("Data product is ready for download.")
+            self._log.info(f"File Size: {size}")
+            self._log.info("Data product is ready for download.")
 
     def _estimatePollPeriod(self, response):
         """
@@ -373,7 +380,7 @@ def _printProductOrderStats(self, fileList: list, runInfo: dict):
 
         # Print run time
         runTime = timedelta(seconds=runInfo["runTime"])
-        print(f"Total run time: {humanize.naturaldelta(runTime)}")
+        self._log.info(f"Total run time: {humanize.naturaldelta(runTime)}")
 
         if downloadCount > 0:
             # Print download time
@@ -381,13 +388,13 @@ def _printProductOrderStats(self, fileList: list, runInfo: dict):
                 txtDownTime = f"{downloadTime:.3f} seconds"
             else:
                 txtDownTime = humanize.naturaldelta(downloadTime)
-            print(f"Total download Time: {txtDownTime}")
+            self._log.info(f"Total download Time: {txtDownTime}")
 
             # Print size and count of files
             natural_size = humanize.naturalsize(size, binary=True)
-            print(f"{downloadCount} files ({natural_size}) downloaded")
+            self._log.info(f"{downloadCount} files ({natural_size}) downloaded")
         else:
-            print("No files downloaded.")
+            self._log.info("No files downloaded.")
 
     def _formatResult(self, fileList: list, runInfo: dict):
         size = 0
diff --git a/src/onc/modules/_OncRealTime.py b/src/onc/modules/_OncRealTime.py
index 5ec55cb..7ce93ec 100644
--- a/src/onc/modules/_OncRealTime.py
+++ b/src/onc/modules/_OncRealTime.py
@@ -9,8 +9,8 @@ class _OncRealTime(_OncService):
     Near real-time services methods
     """
 
-    def __init__(self, config: dict):
-        super().__init__(config)
+    def __init__(self, parent: object):
+        super().__init__(parent)
 
     def getScalardataByLocation(self, filters: dict, allPages: bool):
         """
diff --git a/src/onc/modules/_OncService.py b/src/onc/modules/_OncService.py
index 02eb532..39392dc 100644
--- a/src/onc/modules/_OncService.py
+++ b/src/onc/modules/_OncService.py
@@ -1,14 +1,14 @@
-import logging
-import pprint
 import weakref
-from time import time
-from urllib import parse
 
 import requests
-
-from ._util import _createErrorMessage, _formatDuration
-
-logging.basicConfig(format="%(levelname)s: %(message)s")
+from onc.modules._Messages import (
+    REQ_MSG,
+    RESPONSE_MSG,
+    RESPONSE_TIME_MSG,
+    build_error_message,
+    scrub_token,
+    setup_logger,
+)
 
 
 class _OncService:
@@ -18,6 +18,7 @@ class _OncService:
 
     def __init__(self, parent: object):
         self.parent = weakref.ref(parent)
+        self._log = setup_logger("onc.service", level=self._config("verbosity"))
 
     def _doRequest(self, url: str, filters: dict | None = None, getTime: bool = False):
         """
@@ -44,48 +45,44 @@ def _doRequest(self, url: str, filters: dict | None = None, getTime: bool = Fals
         filters["token"] = self._config("token")
         timeout = self._config("timeout")
 
-        txtParams = parse.unquote(parse.urlencode(filters))
-        self._log(f"Requesting URL:\n{url}?{txtParams}")
-
-        start = time()
         response = requests.get(url, filters, timeout=timeout)
-        responseTime = time() - start
 
-        if response.ok:
-            jsonResult = response.json()
+        if self._config("redact_token"):
+            response_url = scrub_token(response.url)
         else:
-            status = response.status_code
-            if status in [400, 401]:
-                msg = _createErrorMessage(response)
-                raise requests.HTTPError(msg)
-            else:
-                response.raise_for_status()
-        self._log(f"Web Service response time: {_formatDuration(responseTime)}")
-
-        # Log warning messages only when showWarning is True
-        # and jsonResult["messages"] is not an empty list
-        if (
-            self._config("showWarning")
-            and "messages" in jsonResult
-            and jsonResult["messages"]
-        ):
-            long_message = "\n".join(
-                [f"* {message}" for message in jsonResult["messages"]]
-            )
+            response_url = response.url
 
-            filters_without_token = filters.copy()
-            del filters_without_token["token"]
-            filters_str = pprint.pformat(filters_without_token)
+        # Log the url the user submitted.
+        self._log.debug(REQ_MSG.format(response_url))
 
-            logging.warning(
-                f"When calling {url} with filters\n{filters_str},\n"
-                f"there are several warning messages:\n{long_message}\n"
-            )
+        # Display the time it took for ONC to respond in seconds.
+        # The requests.Response.elapsed value is a datetime.timedelta object.
+        responseTime = round(response.elapsed.total_seconds(), 3)  # To milliseconds.
+        self._log.debug(RESPONSE_TIME_MSG.format(responseTime))
+
+        json_response = response.json()
+
+        # Log warning messages if json_response["messages"] is not an empty list
+        if "messages" in json_response and json_response["messages"]:
+            for message in json_response["messages"]:
+                self._log.warning(f"* {message}")
 
-        if getTime:
-            return jsonResult, responseTime
+        if response.status_code in (requests.codes.ok, requests.codes.accepted):
+            self._log.debug(RESPONSE_MSG.format(response.reason, response.status_code))
+            if getTime:
+                return json_response, responseTime
+            return json_response
         else:
-            return jsonResult
+            self._log.error(RESPONSE_MSG.format(response.reason, response.status_code))
+
+            self._log.error(build_error_message(response, self._config("redact_token")))
+
+            if self._config("raise_http_errors"):
+                response.raise_for_status()
+
+            if getTime:
+                return response, responseTime
+            return response
 
     def _serviceUrl(self, service: str):
         """
@@ -115,14 +112,6 @@ def _serviceUrl(self, service: str):
 
         return ""
 
-    def _log(self, message: str):
-        """
-        Prints message to console only when self.showInfo is true
-        @param message: String
-        """
-        if self._config("showInfo"):
-            print(message)
-
     def _config(self, key: str):
         """
         Returns a property from the parent (ONC class)
diff --git a/src/onc/modules/_PollLog.py b/src/onc/modules/_PollLog.py
index 1d32620..e7595cb 100644
--- a/src/onc/modules/_PollLog.py
+++ b/src/onc/modules/_PollLog.py
@@ -1,24 +1,30 @@
+from onc.modules._Messages import setup_logger
+
+
 class _PollLog:
     """
     A helper for DataProductFile
     Keeps track of the messages printed in a single product download process
     """
 
-    def __init__(self, showInfo: bool):
+    def __init__(self, verbosity: str):
         """
-        @param showInfo same as in parent ONC object
+        Parameters
+        ----------
+        verbosity : str
+            Standard logging level string.
         """
         self._messages = []  # unique messages returned during the product order
         self._runStart = 0.0  # {float} timestamp (seconds)
         self._runEnd = 0.0
-        self._showInfo = showInfo  # flag for writing console messages
-        self._doPrintFileCount = True
-        self._lastPrintedDot = False  # True after printing a dot (.) without a newline
+        self._verbosity = verbosity
+        self._log = setup_logger("onc.poll", level=verbosity)
+        self._doLogFileCount = True
 
     def logMessage(self, response):
         """
         Adds a message to the messages list if it's new
-        Prints message to console, or "." if it repeats itself
+        Logs message to logger
         """
         # Detect if the response comes from a "run" or "download" method
         origin = "download"
@@ -35,33 +41,20 @@ def logMessage(self, response):
             # Detect and print change in the file count
             if origin == "run":
                 fileCount = response[0]["fileCount"]
-                if self._doPrintFileCount and fileCount > 0:
-                    self.printInfo(
-                        f"\n   {fileCount} files generated for this data product",
-                        True,
+                if self._doLogFileCount and fileCount > 0:
+                    self._log.info(
+                        f"   {fileCount} files generated for this data product"
                     )
-                    self._doPrintFileCount = False
+                    self._doLogFileCount = False
 
             self._messages.append(msg)
-            self.printInfo("\n   " + msg, sameLine=True)
+            self._log.info("   " + msg)
         else:
-            self.printInfo(".", sameLine=True)
-
-    def printInfo(self, msg: str, sameLine: bool = False):
-        """
-        Conditional printing helper
-        """
-        self._lastPrintedDot = msg == "."
-
-        if self._showInfo:
-            if sameLine:
-                print(msg, end="", flush=True)
-            else:
-                print(msg)
+            # For repeating messages, log at DEBUG level to avoid cluttering INFO logs
+            self._log.debug(msg)
 
     def printNewLine(self):
         """
-        Prints a line break only if the last message printed was a dot (.)
+        Deprecated. Newlines are handled by the logger.
         """
-        if self._lastPrintedDot:
-            print("")
+        pass
diff --git a/src/onc/modules/_util.py b/src/onc/modules/_util.py
index 16db3fb..87bae0e 100644
--- a/src/onc/modules/_util.py
+++ b/src/onc/modules/_util.py
@@ -35,7 +35,11 @@ def saveAsFile(
 def _formatSize(size: float) -> str:
     """
     Returns a formatted file size string representation
-    @param size: {float} Size in bytes
+
+    Parameters
+    ----------
+    size : float
+        Size in bytes.
     """
     return humanize.naturalsize(size)
 
@@ -43,7 +47,11 @@ def _formatSize(size: float) -> str:
 def _formatDuration(secs: float) -> str:
     """
     Returns a formatted time duration string representation of a duration in seconds
-    @param seconds: float
+
+    Parameters
+    ----------
+    secs : float
+        Duration in seconds.
     """
     if secs < 1.0:
         txtDownTime = f"{secs:.3f} seconds"
diff --git a/src/onc/onc.py b/src/onc/onc.py
index 42b1e85..2950019 100644
--- a/src/onc/onc.py
+++ b/src/onc/onc.py
@@ -1,10 +1,12 @@
 import datetime
 import json
+import logging
 import os
 import re
 from pathlib import Path
 
 from dateutil import parser
+from onc.modules._Messages import setup_logger
 from onc.modules._OncArchive import _OncArchive
 from onc.modules._OncDelivery import _OncDelivery
 from onc.modules._OncDiscovery import _OncDiscovery
@@ -27,14 +29,12 @@ class ONC:
 
         - True: Use the production server.
         - False: Use the internal ONC test server (reserved for ONC staff IP addresses).
-    showInfo : boolean, default False
-        Whether verbose script messages are displayed, such as request url and processing time information.
-
-        - True: Print all information and debug messages (intended for debugging).
-        - False: Only print information messages.
-    showWarning : boolean, default True
-        Whether warning messages are displayed. Some web services have "messages" key in the response JSON
-        to indicate that something might need attention, like using a default value for a missing parameter.
+    verbosity : str, default "INFO"
+        The logging verbosity level. Supported values: "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL".
+    showInfo : boolean [Deprecated]
+        Use verbosity="DEBUG" or "INFO" instead.
+    showWarning : boolean [Deprecated]
+        Use verbosity="WARNING" instead.
     outPath : str | Path, default "output"
         The directory that files are saved to (relative to the current directory) when downloading files.
         The directory will be created if it does not exist during the download.
@@ -46,18 +46,34 @@ class ONC:
     >>> from onc import ONC
     >>> onc = ONC()  # Only if you set the env variable "ONC_TOKEN" # doctest: +SKIP
     >>> onc = ONC("YOUR_TOKEN_HERE")  # doctest: +SKIP
-    >>> onc = ONC("YOUR_TOKEN_HERE", showInfo=True, outPath="onc-files")  # doctest: +SKIP
+    >>> onc = ONC("YOUR_TOKEN_HERE", verbosity="DEBUG", outPath="onc-files")  # doctest: +SKIP
     """  # noqa: E501
 
     def __init__(
         self,
         token: str | None = None,
-        production: bool = True,
-        showInfo: bool = False,
-        showWarning: bool = True,
         outPath: str | Path = "output",
+        verbosity: str = "INFO",
+        raise_http_errors: bool = True,
+        redact_token: bool = False,
         timeout: int = 60,
+        production: bool = True,
+        **kwargs,
     ):
+        if "showInfo" in kwargs or "showWarning" in kwargs:
+            import warnings
+
+            warnings.warn(
+                "showInfo and showWarning are deprecated. Use verbosity instead.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            # If verbosity wasn't explicitly changed from default, use showInfo/showWarning to set it
+            if verbosity == "INFO":
+                if kwargs.get("showInfo") is True:
+                    verbosity = "DEBUG"
+                if kwargs.get("showWarning") is False:
+                    verbosity = "ERROR"
         if token is None or token == "":
             token = os.environ.get("ONC_TOKEN")
         if token is None or token == "":
@@ -65,9 +81,14 @@ def __init__(
                 "ONC API token is required. Please provide it as the first argument, "
                 "or set it as the environment variable 'ONC_TOKEN'."
             )
+
+        self.verbosity = verbosity
+        self.redact_token = redact_token
+        self.raise_http_errors = raise_http_errors
+        self._log = setup_logger("onc", self.verbosity)
+
         self.token = re.sub(r"[^a-zA-Z0-9\-]+", "", token)
-        self.showInfo = showInfo
-        self.showWarning = showWarning
+
         self.timeout = timeout
         self.production = production
         self.outPath = outPath
@@ -78,6 +99,8 @@ def __init__(
         self.realTime = _OncRealTime(self)
         self.archive = _OncArchive(self)
 
+        self._log.debug("Initialized ONC module.")
+
     @property
     def outPath(self) -> Path:
         """
@@ -107,6 +130,28 @@ def production(self, is_production: bool) -> None:
         else:
             self.baseUrl = "https://qa.oceannetworks.ca/"
 
+    @property
+    def verbosity(self) -> str:
+        """
+        Return the current verbosity level.
+        """
+        return self._verbosity
+
+    @verbosity.setter
+    def verbosity(self, level: str) -> None:
+        """
+        Set the logging verbosity level for the ONC instance and all its services.
+
+        Supported values: "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL".
+        """
+        self._verbosity = level.upper()
+        setup_logger("onc", self._verbosity)
+
+        # Update all existing loggers that start with 'onc.'
+        for name in logging.root.manager.loggerDict:
+            if name.startswith("onc."):
+                setup_logger(name, self._verbosity)
+
     def print(self, obj, filename: str = "") -> None:
         """
         Pretty print a collection to the console or a file.
@@ -138,6 +183,34 @@ def print(self, obj, filename: str = "") -> None:
             with open(filePath, "w+") as file:
                 file.write(text)
 
+    @property
+    def showInfo(self) -> bool:
+        """
+        [Deprecated] Return whether the logger level is DEBUG.
+        """
+        return self._log.getEffectiveLevel() <= logging.DEBUG
+
+    @showInfo.setter
+    def showInfo(self, value: bool) -> None:
+        """
+        [Deprecated] Set the logger level based on the boolean value.
+        """
+        self.verbosity = "DEBUG" if value else "INFO"
+
+    @property
+    def showWarning(self) -> bool:
+        """
+        [Deprecated] Return whether the logger level is WARNING or lower.
+        """
+        return self._log.getEffectiveLevel() <= logging.WARNING
+
+    @showWarning.setter
+    def showWarning(self, value: bool) -> None:
+        """
+        [Deprecated] Set the logger level based on the boolean value.
+        """
+        self.verbosity = "WARNING" if value else "ERROR"
+
     def formatUtc(self, dateString: str = "now") -> str:
         """
         Format the provided date string as an ISO8601 UTC date string.
diff --git a/src/onc/util/util.py b/src/onc/util/util.py
index b66b5e8..f407837 100644
--- a/src/onc/util/util.py
+++ b/src/onc/util/util.py
@@ -341,9 +341,14 @@ def copyFieldIfExists(fromDic, toDic, keys):
     """
     Copy the field at name from fromDic to toDic only if it exists
 
-    @param fromDic: Origin Dictionary
-    @param toDic: Destination Dictionary
-    @param keys: Array of keys of the elements to copy
+    Parameters
+    ----------
+    fromDic : dict
+        Origin Dictionary.
+    toDic : dict
+        Destination Dictionary.
+    keys : list
+        Array of keys of the elements to copy.
     """
     for key in keys:
         if key in fromDic:
diff --git a/tests/archive_file/test_archivefile_device.py b/tests/archive_file/test_archivefile_device.py
index f6ebdc0..a589f9b 100644
--- a/tests/archive_file/test_archivefile_device.py
+++ b/tests/archive_file/test_archivefile_device.py
@@ -20,9 +20,9 @@ def params_multiple_pages(params):
     return params | {"rowLimit": 2}
 
 
-def test_invalid_param_value(requester, params):
+def test_invalid_param_value(requester, params, err_400):
     params_invalid_param_value = params | {"deviceCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getArchivefile(params_invalid_param_value)
 
 
@@ -32,9 +32,9 @@ def test_invalid_params_missing_required(requester, params):
         requester.getArchivefile(params)
 
 
-def test_invalid_param_name(requester, params):
+def test_invalid_param_name(requester, params, err_400):
     params_invalid_param_name = params | {"deviceCodes": "BPR-Folger-59"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getArchivefile(params_invalid_param_name)
 
 
diff --git a/tests/archive_file/test_archivefile_download.py b/tests/archive_file/test_archivefile_download.py
index 8ae6c9b..ef0900b 100644
--- a/tests/archive_file/test_archivefile_download.py
+++ b/tests/archive_file/test_archivefile_download.py
@@ -4,13 +4,13 @@
 import requests
 
 
-def test_invalid_param_value(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 96"):
+def test_invalid_param_value(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.downloadArchivefile("FAKEFILE.XYZ")
 
 
-def test_invalid_params_missing_required(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 128"):
+def test_invalid_params_missing_required(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.downloadArchivefile()
 
 
diff --git a/tests/archive_file/test_archivefile_location.py b/tests/archive_file/test_archivefile_location.py
index 89fb1b6..9900b21 100644
--- a/tests/archive_file/test_archivefile_location.py
+++ b/tests/archive_file/test_archivefile_location.py
@@ -2,9 +2,9 @@
 import requests
 
 
-def test_invalid_param_value(requester, params_location):
+def test_invalid_param_value(requester, params_location, err_400):
     params_invalid_param_value = params_location | {"locationCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getArchivefile(params_invalid_param_value)
 
 
@@ -14,18 +14,18 @@ def test_invalid_params_missing_required(requester, params_location):
         requester.getArchivefile(params_location)
 
 
-def test_invalid_param_name(requester, params_location):
+def test_invalid_param_name(requester, params_location, err_400):
     params_invalid_param_name = params_location | {"locationCodes": "NCBC"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getArchivefile(params_invalid_param_name)
 
 
-def test_no_data(requester, params_location):
+def test_no_data(requester, params_location, err_400):
     params_no_data = params_location | {
         "dateFrom": "2000-01-01",
         "dateTo": "2000-01-02",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getArchivefile(params_no_data)
 
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 12d434d..3cdb286 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2,6 +2,7 @@
 from pathlib import Path
 
 import pytest
+import requests
 from dotenv import load_dotenv
 from onc import ONC
 
@@ -19,6 +20,16 @@ def requester(tmp_path) -> ONC:
     return ONC(production=is_prod, outPath=tmp_path)
 
 
+@pytest.fixture
+def err_400():
+    return f"{requests.codes.bad} Client Error"
+
+
+@pytest.fixture
+def err_404():
+    return f"{requests.codes.not_found} Client Error"
+
+
 @pytest.fixture(scope="session")
 def util():
     return Util
diff --git a/tests/data_product_delivery/test_data_product_delivery_cancel.py b/tests/data_product_delivery/test_data_product_delivery_cancel.py
index ab347b7..f68b19e 100644
--- a/tests/data_product_delivery/test_data_product_delivery_cancel.py
+++ b/tests/data_product_delivery/test_data_product_delivery_cancel.py
@@ -2,6 +2,6 @@
 import requests
 
 
-def test_invalid_request_id(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+def test_invalid_request_id(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.cancelDataProduct(1234567890)
diff --git a/tests/data_product_delivery/test_data_product_delivery_download.py b/tests/data_product_delivery/test_data_product_delivery_download.py
index faacce4..14c000a 100644
--- a/tests/data_product_delivery/test_data_product_delivery_download.py
+++ b/tests/data_product_delivery/test_data_product_delivery_download.py
@@ -2,6 +2,6 @@
 import requests
 
 
-def test_invalid_run_id(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+def test_invalid_run_id(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.downloadDataProduct(1234567890)
diff --git a/tests/data_product_delivery/test_data_product_delivery_order.py b/tests/data_product_delivery/test_data_product_delivery_order.py
index 7b16df2..06a6524 100644
--- a/tests/data_product_delivery/test_data_product_delivery_order.py
+++ b/tests/data_product_delivery/test_data_product_delivery_order.py
@@ -2,12 +2,13 @@
 import requests
 
 
-def test_invalid_param_value(requester, params):
+def test_invalid_param_value(requester, params, err_400):
     params_invalid_param_value = params | {"dataProductCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.orderDataProduct(params_invalid_param_value)
 
 
+@pytest.mark.slow
 def test_valid_default(requester, params, expected_keys_download_results, util):
     data = requester.orderDataProduct(params)
 
@@ -30,6 +31,7 @@ def test_valid_default(requester, params, expected_keys_download_results, util):
     )
 
 
+@pytest.mark.slow
 def test_valid_no_metadata(requester, params, expected_keys_download_results, util):
     data = requester.orderDataProduct(params, includeMetadataFile=False)
 
@@ -49,6 +51,7 @@ def test_valid_no_metadata(requester, params, expected_keys_download_results, ut
     )
 
 
+@pytest.mark.slow
 def test_valid_results_only(requester, params, expected_keys_download_results, util):
     data = requester.orderDataProduct(params, downloadResultsOnly=True)
 
diff --git a/tests/data_product_delivery/test_data_product_delivery_restart.py b/tests/data_product_delivery/test_data_product_delivery_restart.py
index 4cf1fe5..672ad59 100644
--- a/tests/data_product_delivery/test_data_product_delivery_restart.py
+++ b/tests/data_product_delivery/test_data_product_delivery_restart.py
@@ -2,6 +2,6 @@
 import requests
 
 
-def test_invalid_request_id(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+def test_invalid_request_id(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.restartDataProduct(1234567890)
diff --git a/tests/data_product_delivery/test_data_product_delivery_run.py b/tests/data_product_delivery/test_data_product_delivery_run.py
index 76463c1..0e3dcdc 100644
--- a/tests/data_product_delivery/test_data_product_delivery_run.py
+++ b/tests/data_product_delivery/test_data_product_delivery_run.py
@@ -2,6 +2,6 @@
 import requests
 
 
-def test_invalid_request_id(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+def test_invalid_request_id(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.runDataProduct(1234567890)
diff --git a/tests/data_product_delivery/test_data_product_delivery_status.py b/tests/data_product_delivery/test_data_product_delivery_status.py
index a5eb452..4a48aec 100644
--- a/tests/data_product_delivery/test_data_product_delivery_status.py
+++ b/tests/data_product_delivery/test_data_product_delivery_status.py
@@ -2,6 +2,6 @@
 import requests
 
 
-def test_invalid_request_id(requester):
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+def test_invalid_request_id(requester, err_400):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.checkDataProduct(1234567890)
diff --git a/tests/data_product_delivery/test_integration.py b/tests/data_product_delivery/test_integration.py
index 39014c7..1c67ee5 100644
--- a/tests/data_product_delivery/test_integration.py
+++ b/tests/data_product_delivery/test_integration.py
@@ -1,6 +1,7 @@
 import pytest
 
 
+@pytest.mark.slow
 def test_valid_manual(requester, params, expected_keys_download_results, util):
     """
     Test request -> status -> run -> download -> status.
@@ -35,6 +36,7 @@ def test_valid_manual(requester, params, expected_keys_download_results, util):
     assert data_status_after_download["searchHdrStatus"] == "COMPLETED"
 
 
+@pytest.mark.slow
 def test_valid_cancel_restart(requester, params, expected_keys_download_results, util):
     """
     Test request -> run -> cancel -> download (fail) -> restart -> download.
diff --git a/tests/discover_data_availability/test_data_availability.py b/tests/discover_data_availability/test_data_availability.py
index 1a4a201..a748707 100644
--- a/tests/discover_data_availability/test_data_availability.py
+++ b/tests/discover_data_availability/test_data_availability.py
@@ -12,9 +12,9 @@ def params():
     }
 
 
-def test_invalid_param_value(requester, params):
+def test_invalid_param_value(requester, params, err_400):
     params_invalid_param_value = params | {"locationCode": "INVALID"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDataAvailability(params_invalid_param_value)
 
 
diff --git a/tests/discover_data_products/test_data_products.py b/tests/discover_data_products/test_data_products.py
index 6d149bc..8d75281 100644
--- a/tests/discover_data_products/test_data_products.py
+++ b/tests/discover_data_products/test_data_products.py
@@ -2,25 +2,25 @@
 import requests
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"dataProductCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDataProducts(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"dataProductCodes": "HSD"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDataProducts(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {
         "dataProductCode": "HSD",
         "extension": "txt",
     }
 
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getDataProducts(params_no_data)
 
 
diff --git a/tests/discover_deployments/test_deployments.py b/tests/discover_deployments/test_deployments.py
index b984978..76b3b30 100644
--- a/tests/discover_deployments/test_deployments.py
+++ b/tests/discover_deployments/test_deployments.py
@@ -2,46 +2,46 @@
 import requests
 
 
-def test_invalid_time_range_greater_start_time(requester):
+def test_invalid_time_range_greater_start_time(requester, err_400):
     params_invalid_time_range_greater_start_time = {
         "locationCode": "BACAX",
         "deviceCategoryCode": "CTD",
         "dateFrom": "2020-01-01",
         "dateTo": "2019-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 23"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeployments(params_invalid_time_range_greater_start_time)
 
 
-def test_invalid_time_range_future_start_time(requester):
+def test_invalid_time_range_future_start_time(requester, err_400):
     params_invalid_time_range_future_start_time = {
         "locationCode": "BACAX",
         "deviceCategoryCode": "CTD",
         "dateFrom": "2050-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 25"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeployments(params_invalid_time_range_future_start_time)
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"locationCode": "XYZ123", "deviceCategoryCode": "CTD"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeployments(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"locationCodes": "BACAX", "deviceCategoryCode": "CTD"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeployments(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_400):
     params_no_data = {
         "locationCode": "BACAX",
         "deviceCategoryCode": "CTD",
         "dateTo": "1900-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeployments(params_no_data)
 
 
diff --git a/tests/discover_device_categories/test_device_categories.py b/tests/discover_device_categories/test_device_categories.py
index 45a2a0f..3a39445 100644
--- a/tests/discover_device_categories/test_device_categories.py
+++ b/tests/discover_device_categories/test_device_categories.py
@@ -2,25 +2,25 @@
 import requests
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"deviceCategoryCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeviceCategories(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"deviceCategoryCodes": "CTD"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDeviceCategories(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {
         "deviceCategoryCode": "CTD",
         "deviceCategoryName": "Conductivity",
         "description": "TemperatureXXX",
     }
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getDeviceCategories(params_no_data)
 
 
diff --git a/tests/discover_devices/test_devices.py b/tests/discover_devices/test_devices.py
index 96069aa..1ffa135 100644
--- a/tests/discover_devices/test_devices.py
+++ b/tests/discover_devices/test_devices.py
@@ -2,40 +2,40 @@
 import requests
 
 
-def test_invalid_time_range_greater_start_time(requester):
+def test_invalid_time_range_greater_start_time(requester, err_400):
     params_invalid_time_range_greater_start_time = {
         "deviceCode": "BPR-Folger-59",
         "dateFrom": "2020-01-01",
         "dateTo": "2019-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 23"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDevices(params_invalid_time_range_greater_start_time)
 
 
-def test_invalid_time_range_future_start_time(requester):
+def test_invalid_time_range_future_start_time(requester, err_400):
     params_invalid_time_range_future_start_time = {
         "deviceCode": "BPR-Folger-59",
         "dateFrom": "2050-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 25"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDevices(params_invalid_time_range_future_start_time)
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"deviceCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDevices(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"deviceCodes": "BPR-Folger-59"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getDevices(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {"deviceCode": "BPR-Folger-59", "dateTo": "1900-01-01"}
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getDevices(params_no_data)
 
 
diff --git a/tests/discover_locations/test_locations.py b/tests/discover_locations/test_locations.py
index 2160042..af60aa0 100644
--- a/tests/discover_locations/test_locations.py
+++ b/tests/discover_locations/test_locations.py
@@ -2,40 +2,40 @@
 import requests
 
 
-def test_invalid_time_range_greater_start_time(requester):
+def test_invalid_time_range_greater_start_time(requester, err_400):
     params_invalid_time_range_greater_start_time = {
         "locationCode": "FGPD",
         "dateFrom": "2020-01-01",
         "dateTo": "2019-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 23"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocations(params_invalid_time_range_greater_start_time)
 
 
-def test_invalid_time_range_future_start_time(requester):
+def test_invalid_time_range_future_start_time(requester, err_400):
     params_invalid_time_range_future_start_time = {
         "locationCode": "FGPD",
         "dateFrom": "2050-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 25"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocations(params_invalid_time_range_future_start_time)
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"locationCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocations(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"locationCodes": "FGPD"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocations(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {"locationCode": "FGPD", "dateTo": "1900-01-01"}
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getLocations(params_no_data)
 
 
diff --git a/tests/discover_locations/test_locations_tree.py b/tests/discover_locations/test_locations_tree.py
index e0eb47a..388c06a 100644
--- a/tests/discover_locations/test_locations_tree.py
+++ b/tests/discover_locations/test_locations_tree.py
@@ -2,40 +2,40 @@
 import requests
 
 
-def test_invalid_time_range_greater_start_time(requester):
+def test_invalid_time_range_greater_start_time(requester, err_400):
     params_invalid_time_range_greater_start_time = {
         "locationCode": "ARCT",
         "dateFrom": "2020-01-01",
         "dateTo": "2019-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 23"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocationsTree(params_invalid_time_range_greater_start_time)
 
 
-def test_invalid_time_range_future_start_time(requester):
+def test_invalid_time_range_future_start_time(requester, err_400):
     params_invalid_time_range_future_start_time = {
         "locationCode": "ARCT",
         "dateFrom": "2050-01-01",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 25"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocationsTree(params_invalid_time_range_future_start_time)
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"locationCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocationsTree(params_invalid_param_value)
 
 
-def test_invalid_param(requester):
+def test_invalid_param(requester, err_400):
     params_invalid_param_name = {"locationCodes": "ARCT"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getLocationsTree(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {"locationCode": "ARCT", "dateTo": "1900-01-01"}
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getLocationsTree(params_no_data)
 
 
diff --git a/tests/discover_properties/test_properties.py b/tests/discover_properties/test_properties.py
index a72d88b..6703601 100644
--- a/tests/discover_properties/test_properties.py
+++ b/tests/discover_properties/test_properties.py
@@ -2,25 +2,25 @@
 import requests
 
 
-def test_invalid_param_value(requester):
+def test_invalid_param_value(requester, err_400):
     params_invalid_param_value = {"propertyCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getProperties(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester):
+def test_invalid_param_name(requester, err_400):
     params_invalid_param_name = {"propertyCodes": "conductivity"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getProperties(params_invalid_param_name)
 
 
-def test_no_data(requester):
+def test_no_data(requester, err_404):
     params_no_data = {
         "propertyCode": "conductivity",
         "locationCode": "SAAN",
     }
 
-    with pytest.raises(requests.HTTPError, match=r"404 Client Error"):
+    with pytest.raises(requests.HTTPError, match=err_404):
         requester.getProperties(params_no_data)
 
 
diff --git a/tests/raw_data/test_rawdata_device.py b/tests/raw_data/test_rawdata_device.py
index 2e13959..6fe6585 100644
--- a/tests/raw_data/test_rawdata_device.py
+++ b/tests/raw_data/test_rawdata_device.py
@@ -18,15 +18,15 @@ def params_multiple_pages(params):
     return params | {"rowLimit": 25}
 
 
-def test_invalid_param_value(requester, params):
+def test_invalid_param_value(requester, params, err_400):
     params_invalid_param_value = params | {"deviceCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getRawdata(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester, params):
+def test_invalid_param_name(requester, params, err_400):
     params_invalid_param_name = params | {"deviceCodes": "BPR-Folger-59"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getRawdata(params_invalid_param_name)
 
 
diff --git a/tests/raw_data/test_rawdata_location.py b/tests/raw_data/test_rawdata_location.py
index e9af23f..9889c45 100644
--- a/tests/raw_data/test_rawdata_location.py
+++ b/tests/raw_data/test_rawdata_location.py
@@ -21,21 +21,21 @@ def params_multiple_pages(params):
     return params | {"rowLimit": 25}
 
 
-def test_invalid_param_value(requester, params):
+def test_invalid_param_value(requester, params, err_400):
     params_invalid_param_value = params | {"locationCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getRawdata(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester, params):
+def test_invalid_param_name(requester, params, err_400):
     params_invalid_param_name = params | {"locationCodes": "NCBC"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getRawdata(params_invalid_param_name)
 
 
-def test_no_data(requester, params):
+def test_no_data(requester, params, err_400):
     params_no_data = params | {"dateFrom": "2000-01-01", "dateTo": "2000-01-02"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getRawdata(params_no_data)
 
 
diff --git a/tests/scalar_data/test_scalardata_device.py b/tests/scalar_data/test_scalardata_device.py
index ffbb63e..c85d46a 100644
--- a/tests/scalar_data/test_scalardata_device.py
+++ b/tests/scalar_data/test_scalardata_device.py
@@ -8,15 +8,15 @@ def params_multiple_pages(params_device):
     return params_device | {"rowLimit": 25}
 
 
-def test_invalid_param_value(requester, params_device):
+def test_invalid_param_value(requester, params_device, err_400):
     params_invalid_param_value = params_device | {"deviceCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getScalardata(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester, params_device):
+def test_invalid_param_name(requester, params_device, err_400):
     params_invalid_param_name = params_device | {"deviceCodes": "BPR-Folger-59"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getScalardata(params_invalid_param_name)
 
 
diff --git a/tests/scalar_data/test_scalardata_location.py b/tests/scalar_data/test_scalardata_location.py
index 19ed397..bb38752 100644
--- a/tests/scalar_data/test_scalardata_location.py
+++ b/tests/scalar_data/test_scalardata_location.py
@@ -8,24 +8,24 @@ def params_multiple_pages(params_location):
     return params_location | {"rowLimit": 25}
 
 
-def test_invalid_param_value(requester, params_location):
+def test_invalid_param_value(requester, params_location, err_400):
     params_invalid_param_value = params_location | {"locationCode": "XYZ123"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getScalardata(params_invalid_param_value)
 
 
-def test_invalid_param_name(requester, params_location):
+def test_invalid_param_name(requester, params_location, err_400):
     params_invalid_param_name = params_location | {"locationCodes": "NCBC"}
-    with pytest.raises(requests.HTTPError, match=r"API Error 129"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getScalardata(params_invalid_param_name)
 
 
-def test_no_data(requester, params_location):
+def test_no_data(requester, params_location, err_400):
     params_no_data = params_location | {
         "dateFrom": "2000-01-01",
         "dateTo": "2000-01-02",
     }
-    with pytest.raises(requests.HTTPError, match=r"API Error 127"):
+    with pytest.raises(requests.HTTPError, match=err_400):
         requester.getScalardata(params_no_data)