Invalid Credentials while connecting FedEx account

Shopify Discussion

Topic summary

A user is encountering an “Invalid Credentials” error when attempting to connect their FedEx account to Shopify for custom shipping rates. Despite multiple support sessions with FedEx IT confirming the credentials are correct, Shopify continues to reject them.

Potential causes identified:

  • Using developer/test credentials instead of production credentials
  • Insufficient Shopify plan tier (requires Advanced or Shopify Plus)
  • FedEx account may lack Web Services enabled for rate calculation
  • API authentication differences between FedEx and Shopify systems

Recommended solutions:

  • Regenerate fresh production credentials (Key, Password, Account Number, Meter Number) from FedEx Developer Account
  • Upgrade to Advanced plan or Shopify Plus, or contact Shopify support to add carrier-calculated shipping feature for additional monthly fee
  • Verify FedEx account has Web Services activated
  • Double-check credentials for typos or extra spaces

The discussion remains open with no confirmed resolution yet.

Summarized with AI on October 30. AI used: claude-sonnet-4-5-20250929.
1

We are receiving “Invalid Credentials” when we try to add our FedEx account to get custom rates.

We had a support session multiple times with FedEx IT experts with multiple meter numbers and they can’t see any reason why Shopify is stating that the credentials are bad.

Anyone else have had this issue and if so how was it resolved?

2

Hi @Kanch ,

This issue is common when integrating FedEx with Shopify. Even if FedEx confirms your credentials are correct, Shopify may still reject them due to API authentication differences. Try regenerating new credentials (Key, Password, Account Number, and Meter Number) in your FedEx Developer Account and ensure you’re using production credentials, not test ones. Also, confirm that your Shopify plan supports third-party carrier-calculated shipping rates. If the issue persists, ask Shopify support to check for account-related restrictions.

3

We are currently using the developer mode. Would we need to get on Advanced or Shopify Plus?

Not sure if it matters…but under this developer mode it did let us add the USPS Commercial rates.

4

Yes, to use third-party carrier-calculated shipping rates (like FedEx custom rates) on Shopify, your store must be on the Advanced plan or Shopify Plus. Alternatively, if you’re on the Shopify plan (the mid-tier one), you can enable this feature by contacting Shopify support and paying an additional monthly fee. Developer mode might not support this feature fully, which could be why you’re getting the “Invalid Credentials” error. @Kanch

5

Hi @Kanch

This issue is usually tied to incorrect credentials, API access restrictions, or missing Shopify features.

So, here are few things to check:

  • Make sure you’re using the correct FedEx Account Number, Meter Number, Authentication Key, and Password exactly as provided by FedEx (no extra spaces or typos).
  • Contact FedEx to confirm that your account has Web Services enabled for rate calculation. Some accounts need activation.
  • Shopify requires the Carrier-Calculated Shipping feature (available on the Advanced plan or added to lower plans if paying annually).