After the customer completes their purchase via Klarna, the Payment Request transitions to the COMPLETED state. At this point:

• Klarna returns a payment_token which must be secured through Klarna Webhooks
• You must use this payment_token to authorize the payment within 60 minutes to finalize the transaction.
• Successful authorization will generate a payment_transaction_id required for future transaction management.

The below diagram shows the customer journey and Acquiring Partner workflow, illustrating:

• The handoff from Klarna to the Partner after purchase.
• The sequence from receiving the payment token to finalizing the payment​.

The acquiring partner must use the payment_token to perform a second call to Klarna's Payment Authorize APIAPI.

Sample Request

The payment_token must be passed in the Klarna-Payment-Token HTTP header​.

curl https://api-global.test.klarna.com/v2/accounts/{partner_account_id}/payment/authorize \
-H 'Authorization: Basic <API key>' \
-H 'Content-Type: application/json' \
-H 'Klarna-Payment-Token: krn:payment:eu1:payment-token:...' \
-d '{
      "currency": "USD",
      "request_payment_transaction": {
        "amount": 11800,
        "payment_transaction_reference": "acquiring-partner-transaction-reference-1234"
      }

Upon successful authorization, the response body includes the payment_transaction_id, which you'll use for payment transaction management actions​.

• The endpoint is idempotent, so repeated requests with the same token return the same result, ensuring safe retries​.

Response parameters

Sample response

{
  "payment_transaction_response": {
    "result": "APPROVED",
    "payment_transaction": {
      "payment_transaction_id": "krn:payment:eu1:transaction:6debe89e-98c0-[...]",
      "payment_transaction_reference": "acquiring-partner-transaction-reference-1234",
      "amount": 11800,
      "currency": "USD",
      "payment_funding": {...},
      "payment_pricing": {...},