Sandbox CreatePayment fails with "Not authorized" despite valid credentials

Questions
1

I’m setting up Square payments for a new sandbox application. My sandbox Application ID, Access Token, and Location ID (Default Test Account) all work correctly when I test CreatePayment through the API Explorer — I get a COMPLETED payment.

However, the exact same Access Token, Location ID, and test source_id (cnon:card-nonce-ok), when sent via a direct server-side API call (Cloudflare Worker calling with Authorization: Bearer ), fail every time with:

- Sometimes: [AUTHENTICATION_ERROR/UNAUTHORIZED] “This request could not be authorized.”
- Sometimes: [INVALID_REQUEST_ERROR/BAD_REQUEST] “Not authorized to take payments with location_id=LNSSGJ6H3YXYB”

I’ve confirmed the token is copied exactly (verified via the Explorer’s own generated code/cURL view), tested from a fresh incognito session, redeployed after each change, and confirmed the Application ID matches across both. Can you check whether this Sandbox application/location has card processing fully enabled, or if there’s an account-level restriction blocking direct API calls?

Application ID: sandbox-sq0idb-dozgAFKnykP7wC39CSEa_g
Location ID: LNSSGJ6H3YXYB

3

@BeataAdamczyk - There is no enablement required for card processing. Make sure to switch ALL of the following when switching from sandbox to production:

  • Base URL (https://connect.squareupsandbox.com/v2/payments vs https://connect.squareup.com/… )
  • Application ID
  • Location ID

The errors you are receiving (Not authorized to take payments…) is coming from using the sandbox Location ID for calls to your production environment.

4

Thank you so much for your help.
Beata