Klarna Pay Later

Klarna Pay Later is a payment method provided by Klarna AB, a popular Swedish bank, to payers in Europe.

In Klarna Pay Later, payers can make the payment within the specified number of days. Payers review the items that merchant delivers to them and keep only those items that they intend to purchase and pay for, and return all the unwanted items. For the approved payments, Klarna AB assumes all credit and fraud risk, and pays you the full amount for an order. Ensure to refund each item that payers return to you through the Refund operation. Payers can cancel orders by performing a Refund for the full purchased amount. Klarna Pay Later subsequently invoices payers and collects the payment, providing email notifications and reminders in advance of the payment due date.

Klarna Pay Later is supported in the Mastercard Payment Gateway. This page describes integration details specific to Klarna Pay Later. It is recommended that you read the integration guidelines for browser payments, before building Klarna Pay Later integration.


To offer Klarna Pay Later through the Mastercard Payment Gateway,

  • you must be registered with your browser payments service provider
  • your merchant profile on the Mastercard Payment Gateway must be configured using the details of your account with the browser payments service provider, and
  • you must have a bank account in one of the supported currencies registered against your merchant account at your browser payments service provider.

Klarna Pay Later Transactions

Klarna Pay Later supports transactions originating from multiple countries with their corresponding currencies.

Country Currency
Austria (AUT) EUR
Belgium (BEL) EUR
Denmark (DNK) DKK
Finland (FIN) EUR
Germany (DEU) EUR
Great Britain (GBR) GBP
Netherlands (NLD) EUR
Norway (NOR) NOK
Poland (POL) PLN
Sweden (SWE) SEK
Switzerland (CHE) CHF

Klarna Pay Later Integration

Klarna Pay Later through Hosted Checkout

Hosted Checkout integration allows you to collect payment details from your payers through an interaction that the Mastercard Payment Gateway hosts and displays.

From the API version 52 onward, Klarna Pay Later is automatically available as a payment method once your payment service provider enables and configures you for this payment method.

For details, see Browser Payments via Hosted Checkout Integration.

Klarna Pay Later through Direct Payment

Direct Payment integration allows you to offer the Klarna Pay Later on your own checkout page.

Klarna Pay Later is supported from the API version 52 onward.

Make the Initiate Browser Payment request where sourceOfFunds.type = KLARNA_PAY_LATER and browserPayment.operation = PAY (Klarna Pay Later does not support the Authorize operation).

If your API version is lower than 61, use the sourceOfFunds.type = KLARNA PAY LATER when you make the Initiate Browser Payment request.
Sample Code to Initiate Klarna Pay Later Payment

  "browserPayment": {
    "operation": "PAY",
    "returnUrl": "<your_merchant_URL>"
  "customer": {
    "email": "john.smith@example.com",
    "firstName": "John",
    "lastName": "Smith",
    "mobilePhone": "01234567890"
  "billing": {
    "address": {
      "street": "10 Upper Bank Street",
      "postcodeZip": "E14 5NP",
      "city": "London",
      "country": "GBR"
  "order": {
    "amount": 57.2,
    "currency": "GBP",
    "item": [
        "name": "Blue Jeans",
        "quantity": "1",
        "unitPrice": 70.83,
        "unitDiscountAmount": 48.16,
        "unitTaxAmount": 4.53,
        "detail": {
          "unitTaxRate": 0.2
        "name": "Red Shirt",
        "quantity": "1",
        "unitPrice": 20.83,
        "unitTaxAmount": 4.17,
        "detail": {
          "unitTaxRate": 0.2
        "name": "Shipping & Handling",
        "quantity": "1",
        "unitPrice": 4.17,
        "unitTaxAmount": 0.83,
        "detail": {
        "unitTaxRate": 0.2
  "sourceOfFunds": {
    "type": "KLARNA_PAY_LATER"
Klarna Pay Later Processing Details

In addition to the standard fields required in a browser payment request, provide the following required information for the processing of Klarna Pay Later.

Billing Address and Contact Details

These fields are mandatory unless otherwise stated and are required to support the Klarna Pay Later risk assessment and credit checking processes. The payer's contact information is used to communicate with the payer and to provide electronic invoices and payment notifications.

  • billing.address.city
  • billing.address.country
  • billing.address.postcodeZip
  • billing.address.street
  • customer.email
  • customer.firstName
  • customer.lastName
  • customer.mobilePhone: This field is required when customer.phone is not provided.
  • customer.phone: This field is required when customer.mobilePhone is not provided.

Shipping Address and Contact Details

These fields are mandatory when a value for any shipping.address.* or shipping.contact.* field is provided.

  • shipping.address.city
  • shipping.address.country
  • shipping.address.postcodeZip
  • shipping.address.street
  • shipping.contact.email
  • shipping.contact.firstName
  • shipping.contact.lastName

Order Item Details

Provide complete details about each order item that is purchased so that Klarna Pay Later can correctly validate and display this information to payers and support risk and credit checking processes of Klarna Pay Later.

  • order.item[n].name
  • order.item[n].quantity: The value of this field must be an integer.
  • order.item[n].unitPrice
  • order.item[n].unitDiscountAmount: This field is required when the item has been discounted and must be provided if a value is provided in the order.discount.amount field.
  • order.item[n].unitTaxAmount: This field is required when a payer has to pay tax on the item.
  • order.item[n].detail.unitTaxRate: This field is required when a value for unit tax amount has been provided.

Shipping and Handling

The total tax amount payable for the order is displayed to payers during the payment flow. If the amount payable for shipping and handling includes tax, then you must create an order line to represent shipping and handling so that the discrete tax amount can be provided. If tax does not apply then the shipping and handling amount can be provided in the order.shippingAndHandlingAmount field.

Preferred Language

You can set the language that you prefer Klarna Pay Later to use for pages displayed to payers by providing the browserPayment.preferredLanguage field in the Initiate Browser Payment request. However, for Klarna Pay Later only the primary national language of the billing.address.country or English will be supported.


Klarna Pay Later is at risk of chargebacks. If payers successfully dispute a payment with Klarna Pay Later, then a chargeback transaction will be created on the order. For more information, see chargeback transaction.

If the Klarna Pay Later chargeback is reversed, it does not reflect in the Mastercard Payment Gateway .

How to Interpret the Transaction Result

The table below shows the transaction response codes for the possible scenarios you may encounter after initiating Klarna Pay Later.

Initiate Browser Payment Response
What This Means...
Redirect the payer using the URL provided in the response.
Retrieve Transaction/Retrieve Order Response
What This Means...
The payment is successful.
The Mastercard Payment Gateway is waiting for a notification from the acquirer about the payment result. Try RETRIEVE_TRANSACTION again later or listen to notifications from the Mastercard Payment Gateway.
The payer has cancelled the interaction for this payment. Offer the payer the option to try another payment method.
The payment was declined. Offer the payer the option to try another payment method.
In the case of an ACQUIRER_SYSTEM_ERROR, you may want to inquire with the acquirer about the reason for payment failure, or you can try RETRIEVE_TRANSACTION again.
Treat this as a declined payment. The Mastercard Payment Gateway will make an attempt to ensure the transaction is not successful or will revert the transaction.

Klarna Pay Later Order ID

For the approved payments, the Mastercard Payment Gateway will provide you the ID that Klarna Pay Later has assigned to this order in the field transaction.acquirer.additionalResponseData. This may be useful information for communications you may have directly with Klarna Pay Later.

Web Hook Notifications

If you have subscribed to Mastercard Payment Gateway web hook notifications, you may receive additional notifications for funding status updates and chargebacks.

Testing Your Integration

The Mastercard Payment Gateway provides a browser payments emulator that allows you to test your Klarna Pay Later integration.

Copyright © 2023 Mastercard