refund_out Webhook - NTX Pay API

When it fires

The refund_out webhook type receives the transaction.cash_out.returned event: a transfer you sent was returned by the counterparty’s bank. The corresponding balance is credited back to your account. Common scenarios:

Invalid destination CLABE or closed account
The beneficiary/counterparty bank rejected the transfer after initial acceptance
Return within the SPEI network’s window

Payload

{
  "event": "transaction.cash_out.returned",
  "transactionId": "56789",
  "amount": 50000,
  "currency": "MXN",
  "status": "RETURNED",
  "destinationClabe": "012180001234567890",
  "sourceClabe": null,
  "reference": "9876543",
  "voucher": null,
  "occurredAt": "2026-05-14T09:15:00.000Z"
}

The transactionId is the same as the original cash-out — use it to correlate and mark the payment as returned.

Headers

Header	Value
`x-event-id`	Unique event UUID (use for dedupe)
`X-NTXPay-Signature`	`sha256=<hmac>` of the raw body

Expected Response

200 OK within 10 seconds.

Processing

const event = JSON.parse(rawBody.toString());
if (event.event === 'transaction.cash_out.returned') {
  // The balance credit back has already happened automatically
  await markPayoutReturned(event.transactionId, event.amount);
}

For the complete handler with HMAC validation and dedupe in Node.js, Python, Java, and Go, see Implementation.