Void a transaction

POST

/v1/pos-transactions/{systemTransactionId}/modifications

Request example

Use the following request to void a transaction before settlement.

{
  "merchant": "MERCHANT-1",
  "site": "SITE-1",
  "merchantTransactionId": "POS_002",
  "merchantTransactionDate": "2025-01-27T08:51:02.826Z",
  "amounts": {
    "transaction": 24.99,
    "currencyCode": "GBP",
    "gratuity": 0
  },
  "operation": "Void"
}

Parameter	Description
`merchant` string (≤ 20 characters) required	Your unique merchant identifier, as assigned by PXP.
`site` string (≤ 20 characters) required	Your unique site identifier, as assigned by PXP.
`merchantTransactionId` string (≤ 50 characters) required	The unique identifier for this transaction, as chosen by you.
`merchantTransactionDate` date-time required	The date and time when the initial transaction happened, in ISO 8601 format.
`amounts` object required	Details about the transaction amount.
`amounts.transaction` string required	The value of the transaction. For `Void` operations, this should match the original transaction value.
`amounts.currencyCode` string required	The currency code associated with the transaction, in ISO 4217 format.
`amounts.gratuity` number	The optional gratuity amount.
`operation` string required	The type of modification that you want to make. Set this to `Void`. Possible values: `Capture` `Refund` `Incremental` `Void`

Response example

If your request is successful, you'll receive a 200 response containing a new systemTransactionId and an updated state. You'll also receive a Transaction (Card Cancelled) webhook notification.

{
  "state": "Cancelled",
  "stateData": {},
  "approvalCode": "260643",
  "merchantTransactionId": "POS_002",
  "systemTransactionId": "c1651dba-da35-44f1-bf12-a169d46ced0b",
  "merchantTransactionDate": "2025-04-11T08:37:02.826445+01:00",
  "fundingData": {
    "maskedPrimaryAccountNumber": "222360******0011",
    "expiryMonth": "12",
    "expiryYear": "2049",
    "cardScheme": "MasterCard",
    "gatewayTokenId": "db2d6ff1-d67e-44d2-9e56-4bcdacad753f",
    "providerResponse": {
      "provider": "PXP Financial",
      "code": "00",
      "message": "",
      "merchantId": "",
      "terminalId": "",
      "paymentAccountReference": "",
      "schemeTransactionId": "",
      "merchantAdvice": {
        "code": "",
        "message": ""
      },
      "settlementDate": "2025-04-11T12:03:37.519413+01:00"
      }
   }
}