diff --git a/docs/upload.md b/docs/upload.md
index b96e25f..1249b2a 100644
--- a/docs/upload.md
+++ b/docs/upload.md
@@ -349,13 +349,14 @@ To force a fresh upload (ignoring any existing state), simply delete the state f
 
 The SDK raises specific exceptions for common error cases:
 
-| Exception | Cause |
-|-----------|-------|
-| `FileNotFoundError` | The specified file path does not exist |
-| `ValidationError` | Invalid `DatasetSubmission` or required string inputs |
-| `ValueError` | Missing or invalid required parameter |
-| `PermissionError` | API key is invalid or lacks permissions |
-| `RuntimeError` | Rate limit exceeded or upload failed |
+| Exception | Cause                                                                                                                                                                                             |
+|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `FileNotFoundError` | The specified file path does not exist                                                                                                                                                            |
+| `ValidationError` | Invalid `DatasetSubmission` or required string inputs                                                                                                                                             |
+| `ValueError` | Missing or invalid required parameter                                                                                                                                                             |
+| `AuthenticationError` | The API key is invalid, expired or revoked                                                                                                                                                        |
+| `PermissionError` | When downloading: You have not agreed to the T&C of the dataset. When uploading: your organization is not approved to upload datasets, or the API key was created before the approval was granted |
+| `RuntimeError` | Rate limit exceeded or upload failed                                                                                                                                                              |
 
 ## Using the DatasetSubmission Model
 
diff --git a/src/datacollective/__init__.py b/src/datacollective/__init__.py
index 755d18f..54f0297 100644
--- a/src/datacollective/__init__.py
+++ b/src/datacollective/__init__.py
@@ -6,6 +6,10 @@
     load_dataset,
     save_dataset_to_disk,
 )
+from datacollective.errors import (
+    AuthenticationError,
+    RateLimitError,
+)
 from datacollective.models import (
     DatasetDetails,
     DatasetSubmission,
@@ -36,6 +40,8 @@
     "License",
     "Task",
     "Visibility",
+    "AuthenticationError",
+    "RateLimitError",
     "__version__",
 ]
 
diff --git a/src/datacollective/api_utils.py b/src/datacollective/api_utils.py
index 57bb800..47d3101 100644
--- a/src/datacollective/api_utils.py
+++ b/src/datacollective/api_utils.py
@@ -60,6 +60,7 @@ def _send_api_request(
 
     Raises:
         FileNotFoundError: If the resource is not found (404).
+        AuthenticationError: If the API key is not accepted (401).
         PermissionError: If access is denied (403).
         RateLimitError: If rate limit is exceeded (429).
         ValueError: If API key is missing when authentication is required.
@@ -95,12 +96,23 @@ def _send_api_request(
             f"Resource not found: {method.upper()} {url}"
             + (f" — {detail}" if detail else "")
         )
+    if resp.status_code == 401:
+        from datacollective.errors import AuthenticationError
+
+        detail = _extract_error_detail(resp)
+        raise AuthenticationError(
+            f"Authentication failed. The API key in `{ENV_API_KEY}` is invalid, expired or revoked."
+            " Create a new key on the MDC platform (https://mozilladatacollective.com/api-reference)."
+            + (f"\n{detail}" if detail else "")
+        )
     if resp.status_code == 403:
         detail = _extract_error_detail(resp)
         raise PermissionError(
-            f"Access denied. If the dataset is public, make sure you have read thoroughly and agreed"
-            " to the dataset's Terms & Conditions in its respective page on the MDC platform before downloading. \n"
-            f"{detail}"
+            "Access denied. When downloading, make sure you have read thoroughly and agreed to the dataset's"
+            " Terms & Conditions in its respective page on the MDC platform before downloading."
+            "When uploading, this means your organization is not approved to upload"
+            " datasets yet, or the API key was created before the approval was granted."
+            + (f"\n{detail}" if detail else "")
         )
     if resp.status_code == 429:
         from datacollective.errors import RateLimitError
diff --git a/src/datacollective/errors.py b/src/datacollective/errors.py
index 48be1c9..609a1f9 100644
--- a/src/datacollective/errors.py
+++ b/src/datacollective/errors.py
@@ -46,6 +46,10 @@ class MissingDependencyError(ImportError):
     """Raised when an optional dependency required for a feature is not installed."""
 
 
+class AuthenticationError(RuntimeError):
+    """Raised when the MDC API responds with HTTP 401."""
+
+
 class RateLimitError(RuntimeError):
     """Raised when the MDC API responds with HTTP 429."""