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SumUp Developer

Session Already Processed

Understand the SumUp API Session Already Processed response, common causes, and example payload for completed checkout sessions.

Indicates the checkout has already been processed. Check the transaction status by calling our get transaction endpoint.

Common Causes

Section titled “Common Causes”
  • The checkout has already completed successfully.
  • A duplicate processing request is sent for the same checkout.
  • A retry occurs after the transaction has already been captured.
{
  "type": "https://developer.sumup.com/problem/session-already-processed",
  "title": "Conflict",
  "status": 409,
  "detail": "The checkout session ae98b9cc-2287-4621-afa1-d36ae2ea219d is already processed",
  "instance": "1bfe72b34387"
}