What came back from the payment?

Each of these is retried differently, and some aren't retried at all. Read the resultCode on the response, or the HTTP status when there's no transaction.

Your answers so far

Choose one

Nothing. The request timed out or the connection dropped. You don't know whether the payment happened.
A failure. The platform couldn't complete the request. The resultCode names a fault, such as TimeoutWaitingForProcessorResponse.
A decline from the card issuer or the processor. The resultCode is Decline, or another refusal value.
A refusal by the merchant's own rules. A policy rejection, a review decline, or a 403 screening stop.

What to build

What this means for PCI

This is guidance rather than a compliance determination. Which questionnaire you are eligible for depends on your full environment, so confirm it with your QSA or your acquirer before you rely on it.

Worth knowing

Where to go next

Start over