Apple Pay (Web Payments SDK) — SDK aborts sheet at merchant validation; domain verified, credentials fresh, cards working

Apple Pay on our site opens the payment sheet and self-dismisses in about a second, before Face ID. tokenize() throws UnexpectedError: An unexpected error occurred while using Apple Pay.

We instrumented ApplePaySession and captured the handshake: the session constructs (v3), begin() runs, onvalidatemerchant fires with the apple-pay-gateway.apple.com/paymentservices/startSession validationURL, and the SDK then calls session.abort() without ever calling completeMerchantValidation. The SDK’s merchant-session request to Square’s backend is failing.

Everything on our side is verified:

  • Application: Verified Correct
  • Location: Verified Correct
  • Domain www.*****.com registered under this application, status Verified (2026-08-22); the association file serves HTTP 200 (9,098 bytes)
  • Minimal paymentRequest (US / USD / positive fixed total; no contact requests); tokenize() called synchronously in the click handler
  • Production access token renewed 2026-08-23 after the console’s Locations page reported “Access token is missing” — the abort is unchanged after renewal
  • Card payments through the same application and location work: live production charges completed before and after the token renewal (most recent 2026-08-23, 14:33 UTC)
  • Reproduced on iOS 26 (Safari and Chrome), fresh sessions, across 2026-08-22 and 2026-08-23

it appears Apple Pay on the web is not fully provisioned for this seller account despite the Verified domain.

I’d like to see if I can reproduce this and track some of the internal API logs. Could you post your AppID and a timestamp (date time + timezone) I can use to trace it?

It would also help if you had some sample code showing how you are setting up the web payments SDK and any error messages reported to the browser’s devtools