Advance Payment

The API endpoint to make an advance payment is POST /Smart/Transaction/STX_xxx/start/prepaid. There is no prior authorization needed.

Example Request
POST /api/v2/Smart/Transactions/STX_xxx/start/prepaid HTTP/1.1
Authorization: Bearer qb56tjj1bcvo9n2nj4u38k84lo
Content-Type: application/json
Accept: application/json

If everything is fine, the API responds with 200 OK:

Example Response
HTTP/1.1 200 OK
Content-Type: application/json
"object": "smart.transactions",
// ...
"transactions": [
"object": "payment.transactions",
// ...
"created": "2020-03-27T10:55:23+01:00",
"status": "pending",
// ...
"application_context": {
"return_urls": {
"url_success": "",
"url_error": "",
"url_abort": ""
"checkout_links": null,
"payment_links": {
"creditcard": null
"debit": null
"invoice": null
"prepaid": null
"general": null

The Smart Transaction will change to status pending to signalize that we still wait for the payment. When the payment has arrived, it switches to ok (intent sale or authorization), and you can deliver.