Partner initiated Payment Authorization

Authorize a Payment Transaction with Klarna using a server-side integration when the customer is not present. As an Acquiring Partner, you'll collect payment context from the Partner, call authorizePayment with a stored customer token, handle authorization outcomes, and return results — all without requiring customer interaction. This flow is ideal for subscription renewals, scheduled payments, and other Partner-initiated transactions.

Before starting, ensure the following:

• A valid Partner Account with API credentials
• A valid Customer Token obtained through Payment Tokenization
• Backend capability to store and manage customer tokens securely
• Payment context and transaction details ready for authorization

Once the Partner initiates Payment Authorization (for example, a subscription renewal):

1. 1.
   The Partner initiates Payment Authorization through the Acquiring Partner's internal customer token identifier and payment details
2. 2.
   The Acquiring Partner forwards the payment context to Klarna by calling authorizePayment with the customer token
3. 3.
   Klarna evaluates the request and returns one of the following results:

   • 3.1.
     APPROVED
   • 3.2.
     DECLINED
4. 4.
   The Acquiring Partner handles the result and returns the outcome to the Partner

Partners can initiate token charges in two ways:

• Direct Klarna integration: Partners with their own Klarna integration use a Customer Token to initiate the charge and provide the resulting Klarna Network Session Token to the Acquiring Partner
• Using Acquiring Partner's token: Partners use the Acquiring Partner's internal customer token identifier, which the Acquiring Partner maps to the corresponding Klarna Customer Token Update the Partner-facing API to collect the following data points from the Partner for partner-initiated payment scenarios:

Requirements

• Use exact parameter names klarna_network_session_token and klarna_network_data in the Partner-facing API to ensure Partners can easily identify and use them.
• Forward all parameters unmodified to Klarna.
• Parameter validation must not be more restrictive than Klarna's authorizePayment.
• Support all printable UTF-8 characters.
• Supplementary purchase data handling:

  • Map your existing Partner-facing fields (line items, customer billing address, shipping, purchase reference) into supplementary_purchase_data when calling Klarna
  • Don't add new Partner-facing fields "just for Klarna" if you already have equivalent fields in your existing schema. Avoid forcing Partners to submit the same data twice using parallel structures

The authorizePayment API is used to start the payment process on Klarna whether they are with or without customer presence.

In the request to authorizePayment, specify the following parameters:

curl https://api-global.test.klarna.com/v2/accounts/{partner_account_id}/payment/authorize \
  -H 'Authorization: Basic <API key>' \
  -H 'Klarna-Customer-Token: <token>' \
  -H 'Klarna-Network-Session-Token: <token>' \
  -H 'Content-Type: application/json' \
  -d '{
        "currency": "USD",
        "request_payment_transaction": {
          "amount": 11800,
          "payment_option_id": "***",
          "payment_transaction_reference": "finalize-ref-1234"
        },

When performing Partner-initiated authorization through authorizePayment, Klarna returns a response that reflects the result of the authorization. Since this flow includes a request_payment_transaction in the request and the customer is not present, the response will always contain a payment_transaction_response object with a result field that indicates the outcome.

For partner-initiated flows without customer interaction, the result has the following possible values:

The response schema is as follows:

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

Map the Klarna authorization result to the Partner-facing API response.

When available, also return:

• klarna_network_response_data

Requirements

• All returned data must be forwarded without modification.

After implementing partner-initiated payment authorization, explore these related topics:

• Manage payment transactions - Capture, refund, and cancel authorized payments
• Set up webhooks - Configure and manage webhook subscriptions for payment events
• authorizePayment reference — Complete API specification and parameters