You can cancel a former transaction with the receipt number before the end-of-day report is done.

The endpoint for the cancellation of terminal transactions is POST /api/v2/Smart/Transactions/{receipt_number}/cancelTrx:

Request
POST /api/v2/Smart/Transactions/3/cancelTrx HTTP/1.1
Host: connect-testing.secuconnect.com
Authenticate: Bearer qb56tjj1bcvo9n2nj4u38k84lo
Accept: application/json

This request is blocking. Secuconnect API only after the payment terminal has processed the cancellation.

If everything is fine, the API responds with 200 OK and the representation of the cancelled Smart Transaction:

Response
HTTP/1.1 200 OK
Content-Type: application/json
...
 
{
"object": "smart.transactions",
"id": "STX_3HXQQBSVK2XWNAX7ESCZH9NZY3YZAZ",
// ...
"transactions": [],
"created": "2021-02-25T08:47:25+01:00",
"updated": "2021-02-25T08:49:58+01:00",
"status": "cancelled",
// ...
"receipt_number": 3,
// ...
}

The new status is cancelled.

Customer and merchant receipt for the payment are kept unchanged in the Smart Transaction.