There are a couple of possible reasons why you'll get Authentication Failed message when you try to connect your FedEx account.
1. Your FedEx account is not a UK account.
If your FedEx account is not a UK account, then you'll get an Authentication Failed message when you hit the Test Connection button within your FedEx integration settings even if you are using the correct credentials.
This is a normal behavior and you should still be able to book your shipments as normal. If not, please check that you have the correct details and if still no go, then feel free to contact us.
2. You have not filled in your Shipping Location, including your contact information. Adding this should rectify the issue.
3. The address on your Shipping Location page and your FedEx account (portal) doesn't match.
Please check that the address registered on FedEx website is the same as what you have entered on your Shiptheory account. If not, then that is the reason why you are unable to get a successful authentication.
If you have checked all of these and still can't get the connection to work, please contact us.