There are two reasons you can encounter "Authentication error" while using ParcelForce.
Invalid or expired "production credentials"
Note: Your "production credentials" are separate from your regular parcelforce account.
Reach out to [email protected] to obtain your "production credentials" for ParcelForce
Click on EDIT next to your ParcelForce account.
Change your credentials to the updated credentials.
An issue with the Department ID
We have noted some accounts need to experiment with the "Department ID" of their Parcelforce account to get it to work.
Follow the instructions above but then in the center, under "Production Credentials":
Try entering a number "1" and try buying your shipment again and see if it will work. If not, try inputting a number "2" instead, and click UPDATE to complete the EDIT.
Still having issues?
For further assistance, contact EasyPost.