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Klarna for API only

Add Klarna to an existing API-only integration.

Accept Klarna payments using our APIs, and build your own payment form to have full control over the look and feel of your checkout page.

With our API-only integration, you can accept Klarna payments using either:

  • The Klarna widget: The shopper completes the payment in your checkout. For more information about the Klarna widget, see the Klarna documentation.

  • Redirect to Klarna: The shopper is redirected to Klarna to complete the payment.

When making a Klarna payment:

  1. Provide information about the purchased items by specifying lineItems in your payment request.
  2. Indicate in your payment request if you want to use the Klarna widget or redirect to Klarna.
  3. Capture the payment after the goods have been sent. This triggers the payment instructions to be sent to the shopper.

Before you begin

These instructions explain how to add Klarna to your existing API-only integration. The API-only integration works the same way for all payment methods. If you haven't done this integration yet, refer to our API-only integration guide.

Before starting your Klarna integration:

  1. Make sure that you have set up your back end implementation.
  2. Add Klarna in your test Customer Area.

Build your payment form for Klarna

When making a Klarna payment, collect the following shopper details:

Shopper detail Description Required
Shopper name The shopper's full name and gender, if specified.
Shopper email The shopper's email address. This is where Klarna will send the invoice. -white_check_mark-
The billing address The postal address to be included on the invoice.

For improved conversion rates, we strongly recommend that you collect the shopper name and the billing address.

If you are using the /paymentMethods endpoint to show the available payment methods to the shopper, specify in your request one of the following combinations of countryCode and amount.currency, depending on which Klarna payment method you want to accept:

Country countryCode amount.currency Pay now Pay later Pay over time
Australia AU AUD -x- -x- -white_check_mark-
Austria AT EUR -white_check_mark- -white_check_mark- -white_check_mark-
Belgium BE EUR -white_check_mark- -white_check_mark- -x-
Canada CA CAD -x- -x- -white_check_mark-
Czech Republic CZ CZK -x- -x- -white_check_mark-
Denmark DK DKK -x- -white_check_mark- -x-
Finland FI EUR -x- -white_check_mark- -white_check_mark-
France FR EUR -x- -x- -white_check_mark-
Germany DE EUR -white_check_mark- -white_check_mark- -white_check_mark-
Greece GR EUR -x- -x- -white_check_mark-
Ireland IE EUR -x- -x- -white_check_mark-
Italy IT EUR -x- -x- -white_check_mark-
Norway NO NOK -x- -white_check_mark- -white_check_mark-
Poland PL PLN -x- -white_check_mark- -x-
Portugal PT EUR -x- -x- -white_check_mark-
Romania RO RON -x- -x- -white_check_mark-
Spain ES EUR -x- -x- -white_check_mark-
Sweden SE SEK -white_check_mark- -white_check_mark- -white_check_mark-
Switzerland CH CHF -white_check_mark-
See note 3
See note 3
The Netherlands NL EUR -white_check_mark- -white_check_mark- -white_check_mark-
United Kingdom GB GBP -x- -white_check_mark- -white_check_mark-
United States US USD -x- -x- -white_check_mark-

3 If you want to offer Klarna in Switzerland, contact our Support Team.

The /paymentMethods response contains:

  • paymentMethod.type: klarna_paynow for Klarna — Pay Now.
  • paymentMethod.type: klarna for Klarna — Pay later.
  • paymentMethod.type: klarna_account for Klarna — Pay over time.

We provide logos for Klarna which you can use on your payment form. For more information, refer to Downloading logos.

Make a payment

Klarna requires shopper details such as name and address to approve a payment. To improve shopper experience and conversion rates, provide these details in the payment request and make sure that the parameters in the request match.

Send the shopper name and billing address in the request.

  • We recommend that you send the shopper name and billing address to improve the shopper experience. If not provided in the request, Klarna will ask the shopper to provide these parameters in the checkout page.

Make sure that the country, the currency, and the shopper locale in the request are compatible.

  • Klarna will only approve the payment if the country it is made from matches the currency and the country specified in the billing address.
  • The Klarna checkout page can only be rendered in another language if the specified locale matches the country and currency used in the request. By default, the checkout page is rendered is English (en-US).

The following table shows the possible combinations that you can send in a payment request:

Country countryCode
amount.currency shopperLocale
Austria AT EUR en_US de_AT
Belgium BE EUR en_US nl_BE, fr_BE
Denmark DK DKK en_US da_DK
Finland FI EUR en_US fi_FI, sv_FI
France FR EUR en_US fr_FR, en_FR
Germany DE EUR en_US de_DE
Italy IT EUR en_US it_IT
Norway NO NOK en_US nb_NO
Spain ES EUR en_US es_ES
Sweden SE SEK en_US sv_SE
Switzerland CH CHF en_US de_CH, fr_CH, it_CH
The Netherlands NL EUR en_US nl_NL
United Kingdom GB GBP en_US en_GB
United States US USD en_US es_US

Make a payment request

From your server, make a /payments request, specifying:

  • paymentMethod.type: The type of Klarna payment the shopper wants to use. Possible values:

    • klarna_paynow for Klarna — Pay Now.
    • klarna for Klarna — Pay later.
    • klarna_account for Klarna — Pay over time.

  • How you want the shopper to complete the payment:

    • On your own checkout using the Klarna widget: add paymentMethod.subtype with a value of sdk. For example:

    • Using a redirect to Klarna: don't add the paymentMethod.subtype parameter.

Parameter name Required Description
lineItems -white_check_mark- Price and product information about the purchased items.
Klarna only approves the payment if the total amount specified in lineItems matches the amount.value, and each line item contains a description.
You can optionally specify productUrl and imageUrl to include a link to and a picture of the purchased items in the invoice.
shopperEmail -white_check_mark- The shopper's email address. This is where Klarna will send the payment instructions.
For requirements on this field, see Klarna's documentation.
shopperReference -white_check_mark- A unique reference to identify the shopper (minimum length three characters).
shopperName The shopper's full name.
Recommended to increase conversion rates. If you don't include it, Klarna will ask the shopper to provide this in the checkout page.
For requirements on this field, see Klarna's documentation.
billingAddress The postal address of the shopper.
Recommended to increase conversion rates. If you don't include it, Klarna will ask the shopper to provide this in the checkout page.
For requirements on this field, see Klarna's documentation.
deliveryAddress The postal address where the purchased goods should be delivered. If not provided, this is the same as the billing address.
For requirements on this field, see Klarna's documentation.
shopperLocale A combination of language code and country code to define the language of the Klarna checkout page. By default, the checkout page is rendered is English.

This has to match the countryCode and currency used in the request. For more information, see Klarna's documentation.
countryCode -white_check_mark- The shopper's country.

This has to match the country of the billingAddress.
telephoneNumber The shopper's telephone number, if provided.
For requirements on this field, see Klarna's documentation.
For some products or business models, Klarna might require additional information. If you need to send in this information, specify here the Base64 encoded JSON of the attachment.body value described in Klarna's documentation.

If the recipient name is different from the shopperName, specify the recipientFirstName and recipientLastName to share the recipient name with Klarna. If they are the same, only the shopperName will be shared with Klarna.

A sample /payments request for Klarna — Pay later using a redirect:

The response to your  /payments call depends on whether you are using:

The Klarna widget

The response to your  /paymentsrequest contains:

  • resultCodePending

  • paymentData: A value that you need to submit to the /payments/details endpoint later.

  • redirect: Object containing a client token.

  1. Use the client token to populate the Klarna widget.
    This opens an iframe where the shopper has to enter their details.

  2. After the shopper has submitted the details, you will receive an authorization_token. For more information about the authorization_token, see the Klarna documentation.

  3. Verify the result of the payment by making a /payments/details call, providing:

    • authorization_token: You received this in the previous step.

    • paymentData: The value from the response to your  /payments call.


    The response contains a pspReference, which is our unique identifier for this payment, and a resultCode.

  4. Use the resultCode to present the payment result to your shopper.

Redirect to Klarna

The /payments response contains an action object with the information needed to redirect the shopper.

Handle the redirect

  1. To complete the payment, redirect the shopper to the action.url returned in the /payments response.

When using the HTTP GET method:
For security reasons, when displaying the redirect in the app, we recommend that you use SFSafariViewController for iOS or Chrome Custom Tabs for Android, instead of WebView objects. Also refer to the security best practices for WebView.

  1. After the shopper is redirected back to your website, check the payment result by making a POST /payments/details request, specifying:

    • details: Object that contains the URL-decoded redirectResult returned when the shopper was redirected back to your site.

You receive a response containing:

  • resultCode: Use this to present the result to your shopper.
  • pspReference: Our unique identifier for the transaction.

Present the payment result

Use the resultCode from the /payments/details response to present the payment result to your shopper. The resultCode values you can receive for Klarna are:

resultCode Description Action to take
Authorised The payment was successful. Inform the shopper that the payment was successful. After the goods have been sent, you also need to capture the payment.
Cancelled The shopper cancelled the payment. Ask the shopper whether they want to continue with the order, or ask them to select a different payment method.
Refused The payment was refused by Klarna, as it didn't pass their risk checks. Ask the shopper to try the payment again using a different payment method.

When a payment is refused by Klarna, the shopper sees the following message:

Capture the payment

If the capture delay is set to immediate and you comply with Klarna's Scheme Rules of shipping within 24 hours, then you can configure automatic capture when adding Klarna in your live Customer Area. Otherwise, you must manually capture Klarna payments within 90 days after authorization, even if you enable automatic capture on your merchant account. If the manual capture is not performed within 90 days, the authorization will expire.

Manual captures

To manually capture a Klarna payment, specify in your call to the /capture endpoint:

  • merchantAccount: The name of your merchant account that is used to process the payment.
  • modificationAmount: The amount that the shopper should pay. This must be the same as the authorised amount.
  • originalReference: The original pspReference of the payment that you want to capture. This reference is returned in the response to your payment request, and in the AUTHORISATION webhook.
  • additionalData.openinvoicedata: Information to include on the invoice:

    Price and product information

    Although some of the field names are different, the information in additionalData.openinvoicedata is the same as what you provided in lineItems when making a /payments request. The following table shows how the fields correspond.

    openinvoicedata Corresponds with Description Required
    itemAmount lineItems.amountExcludingTax The price for one item, without the tax, in minor units. -white_check_mark-
    itemVatPercentage lineItems.taxPercentage The tax percentage, in minor units. -white_check_mark-
    itemVatAmount lineItems.taxAmount The tax amount for one item, in minor units.

    Shipping and tracking information (optional)

    You can optionally use additionalData.openinvoicedata to include shipping and tracking information. This adds information about how the products are shipped to the deliveryAddress that you specified in the /payments request. The shipping and tracking information maps to Klarna's shipping info object.

    If you have the shipping and tracking information at the time of the capture, we recommend that you send it as it will improve the overall shopper experience. Klarna includes this information in their app, where the info is updated based on the tracking details.

    • If all items are shipped with the same provider, specify the shipping and tracking information once, as shown in the capture example below.
    • If one or more items in the order are shipped with different a different provider or tracking details, specify the shipping and tracking information as an array.
    • You cannot specify different delivery addresses for a single order with multiple items.
    openinvoicedata Corresponds with Klarna's shipping_info object Description
    shippingCompany shipping_company The name of the shipping company, as specific as possible. Maximum 100 characters. If there are multiple shipping companies, specify an array. For example: DHL SE or [DHL SE, PostNord]
    shippingMethod shipping_method Shipping method. Possible values:
    • PickUpStore
    • Home
    • BoxReg
    • BoxUnreg
    • PickUpPoint
    • Own
    • Postal
    • DHLPackstation
    • Digital
    • Undefined
    trackingNumber tracking_number Tracking number for the shipment. Maximum 100 characters. If there are multiple tracking numbers, specify an array. For example: 050823 or [050823, 050824]
    trackingUri tracking_uri URI where the customer can track their shipment. Maximum 1024 characters.
    returnShippingCompany return_shipping_company The name of the shipping company for the return shipment, as specific as possible. Maximum 100 characters. For example: DHL SE
    returnTrackingNumber return_tracking_number Tracking number for the return shipment. Maximum 100 characters.
    returnTrackingUri return_tracking_uri URI where the customer can track their return shipment. Maximum 1024 characters.

You will receive a /capture response containing a pspReference associated with this request. Once we have processed your request, you will also receive a CAPTURE webhook. For more information, refer to Capture.

Partial captures

To partially capture a Klarna payment, specify in your call to the /capture endpoint:

  • modificationAmount: The amount that the shopper should pay. This should be less than the authorised amount.
  • additionalData.openinvoicedata: Price, product and optionally shipping and tracking information for the items that the shopper should pay for, to be included on the invoice. For the partial capture to be successful, the amounts stated in openinvoicedata need to be correct. You can use the same fields as listed in the manual captures section.

For more information and an example, refer to Invoice lines.

Recurring payments

To make recurring Klarna payments you need to:

  1. Create a shopper token.
  2. Use the token to make future payments for the shopper.

Not all Klarna payment methods or countries support recurring payments. For information about the availability of recurring payments, refer to Klarna documentation.

Create a token

To create a token, include in your /payments request:

  • storePaymentMethod: true
  • shopperReference: Your unique identifier for the shopper.

When the payment has been settled, you receive a webhook containing:

  • originalReference: The pspReference of the initial payment.
  • pspReference: This is the token that you need to make recurring payments for this shopper.

Make sure that your server is able to receive RECURRING_CONTRACT as part of your standard webhooks. You can enable the RECURRING_CONTRACT event code in the webhook settings page.

Make a payment with a token

To make a payment with the token, include in your /payments request:

  • shopperReference: The unique shopper identifier that you specified when creating the token.
  • paymentMethod.storedPaymentMethodId: The pspReference from the RECURRING_CONTRACT webhook. You can also get this value by using the /listRecurringDetails endpoint.
  • shopperInteractionContAuth.
  • recurringProcessingModel: The type of recurring payment that you want to make. Possible values:
recurringProcessingModel Description
CardOnFile Online purchase where shopper is actively making a purchase using their previously stored payment details.
Subscription A series of transactions with fixed or variable amounts, following a fixed time interval. This is the default value for payment requests where shopperInteractionContAuth.
UnscheduledCardOnFile Contracts that occur on a non-fixed schedule using stored payment details. For example, automatic top-ups when cardholder's balance drops below certain amount.

When making a recurring payment, you also need to provide all the parameters required for a Klarna payment request.

A sample request for Klarna — Pay now, when the shopper is actively making a purchase using previously stored payment details:

Test and go live

Before accepting live payments, test your integration using the test environment and sample data provided by Klarna.

You can then check the status of Klarna test payments in your Customer Area > Transactions > Payments.

Before you go live

Make sure that:

  • You have added Klarna in your live Customer Area.
  • You have considered Klarna's legal and privacy information.
  • You follow the Klarna guidelines on how to display Klarna in your checkout.
  • The invoice lines and VAT are displayed correctly on Klarna's pages.
  • If a shopper gets rejected by Klarna, you offer them another payment method.
  • You pass the shopper's name and address in your payment request. While optional, providing these parameters improves the shopper experience and increases conversion rates.

Testing in live environment

If you are going to test Klarna payments once you are in the live environment, make sure that you:

  • Provide real shopper data. For example, your real name, personal email, personal mobile, and home and billing address. Don't provide a company address as billing address.
  • Choose an item with a reasonable amount that meets Klarna's minimum requirements. For example, for Pay over time, Klarna requires a minimum amount of GBP 35. Klarna can reject a request if the product is too expensive and they do not have enough transaction history for the shopper.
  • Don't perform multiple tests in a short span of time from the same device or IP address. This will trigger velocity rule checks, which will lead to the transaction being rejected.

If the conditions above are not met, you might receive a resultCode of Refused. The shopper sees a page with an "Option Not Available" message instead of the Klarna Payments widget. Note that these checks are bypassed in test and are only applied in the live environment.

See Klarna raw acquirer responses for the most common responses for successful, refused, failed or cancelled transactions.

See also