How can I resolve the 'Forbidden - Caller Does Not Have Permission' error in n8n's Google Sheets integration?

Below are a few things to double-check and try when you get the “Forbidden - perhaps check your credentials? The caller does not have permission.” error while updating your Google Sheets database in n8n:

• Scopes:
  Ensure that your OAuth credential in n8n includes the proper scopes. For Google Sheets, you’ll typically need https://www.googleapis.com/auth/spreadsheets and sometimes also https://www.googleapis.com/auth/drive.file (depending on your operation). If the scope isn’t included or is misspelled, Google may deny access.

• OAuth Credential Setup:
  Although you mentioned you used the same email for your Google Cloud Console and n8n setup, it’s worth rechecking that you’ve completed the final step in your n8n credential (i.e. clicking “Sign in with Google”) so that the access token is valid. Sometimes re-authenticating can help.

• Service Account Considerations:
  If you’re using a Service Account instead of standard OAuth2 credentials, make sure that domain-wide delegation (or “Impersonate a User”) is enabled and that the sheet is shared with the service account’s email. Without it, Google won’t authorize updates.

• API & Permissions:
  Double-check that the Google Sheets API is fully enabled on the specific project where your OAuth credentials were created. Although you mentioned it’s enabled, sometimes enabling additional APIs (like Google Drive API, if needed for drive-based operations) can resolve permission issues.

Revisit the credential configuration steps in your n8n Google Sheets integration to ensure that every step (from creating the Google Cloud project to finishing the n8n credential) has been carried out exactly as per the documentation. This detailed verification should resolve the “forbidden” error.

Hope this helps!

Below is a checklist of what to review in order to resolve this error:

1. Verify the Credential Type and Scopes

• OAuth2 Credentials:
  Make sure that the credentials in n8n include the required scopes. For Google Sheets updates, you typically need:

  • https://www.googleapis.com/auth/spreadsheets
  • And, if needed for file-level access, https://www.googleapis.com/auth/drive.file
    If these scopes are not added (or are entered with an incorrect separator), the request might be rejected. In n8n, when editing your Google Sheets credentials, enter the scopes in a space-separated list.

• Service Account Credentials:
  If you’re using a Service Account, confirm that you’ve enabled domain-wide delegation. Also, the spreadsheet must be shared with the service account’s email address—not just your own.
  For additional details on checking and setting up delegation, refer to the “Finish your n8n credential” section in the Google Service Account documentation in n8n.

2. Double-Check API Enablement

Even though you mentioned the Sheets API is enabled, verify that:

• You’re using the correct project (the one that the n8n credential is referencing).
• If your workflow accesses files on Drive, the Drive API may also need to be enabled.

3. Confirm Credential Ownership and Sharing Permissions

• When using OAuth2, ensure that the account you signed in with (and whose credentials you’re using) has been granted editing permissions on the target spreadsheet.
• For a Service Account, be sure to share the spreadsheet with the email address associated with the service account.

4. Review the OAuth Redirect URL

If an OAuth redirect URL is misconfigured or missing from your Google Cloud project’s credentials, Google may reject the token exchange request. Verify that your redirect URL from n8n is properly added to your Google Cloud Console under Authorized Redirect URIs.

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By going through these steps, you should be able to identify what might be causing the “Forbidden - perhaps check your credentials? The caller does not have permission” error. If the error persists, recheck each step carefully, particularly the configured scopes and whether the used account has the correct access rights.

Hope this helps resolve your issue!