Accept a Klarna payment

Learn how to accept Klarna, a global buy now, pay later payment method.

Unified line items with Klarna

To optimize approval rates when you integrate with Klarna, include line_items data to represent what’s in a shopper’s cart. For early access, see Payments line items.

Web

Mobile

Stripe users can use the Payment Intents API—a single integration path for creating payments using any supported method—to accept Klarna payments from customers in Klarna’s supported countries.

Klarna is a single use, immediate notification payment method that requires customers to authenticate their payment. Customers are redirected to a Klarna page, where they select among multiple payment options (immediate full payment, payment in installments, or deferred payment). When the customer accepts the terms, Klarna guarantees that the funds are available to the customer and transfers the funds to your Stripe account. The customer repays Klarna according to their selected payment option.

Note

Before you start the integration, make sure your account is eligible for Klarna by navigating to your Payment methods settings.

Set up Stripe
Server-side

First, you need a Stripe account. Register now.

Use our official libraries for access to the Stripe API from your application:

Create a PaymentIntent
Server-side

A PaymentIntent is an object that represents your intent to collect payment from a customer and tracks the lifecycle of the payment process through each stage. First, create a PaymentIntent on your server.

If you already have an integration using the Payment Intents API, add klarna to the list of payment method types for your PaymentIntent.

Klarna requires only customer currency. If you pass the optional shipping parameter, ensure these fields are defined and not empty: name, address.line1, city, country, and postal_code.

Retrieve the client secret

The PaymentIntent includes a client secret that the client side uses to securely complete the payment process. You can use different approaches to pass the client secret to the client side.

Retrieve the client secret from an endpoint on your server, using the browser’s fetch function. This approach is best if your client side is a single-page application, particularly one built with a modern frontend framework like React. Create the server endpoint that serves the client secret:

And then fetch the client secret with JavaScript on the client side:

(async () => {
  const response = await fetch('/secret');
  const {client_secret: clientSecret} = await response.json();
  // Render the form using the clientSecret
})();

Submit the payment to Stripe
Client-side

In this step, you’ll complete Klarna payments on the client with Stripe.js.

Set up Stripe.js

When a customer clicks to pay with Klarna, we recommend using Stripe.js to submit the payment to Stripe. Stripe.js is our foundational JavaScript library for building payment flows. It automatically handles complexities like the redirect described below, and enables you to easily extend your integration to other payment methods in the future. Include the Stripe.js script on your checkout page by adding it to the head of your HTML file.

checkout.html
<head>
  <title>Checkout</title>
  <script src="https://js.stripe.com/v3/"></script>
</head>

Create an instance of Stripe.js with the following JavaScript on your checkout page.

script.js
// Set your publishable key: remember to change this to your live publishable key in production
// See your keys here: https://dashboard.stripe.com/apikeys
var stripe = Stripe('pk_test_TYooMQauvdEDq54NiTphI7jx'
);

Rather than sending the entire PaymentIntent object to the client, use its client secret from step 2. This is different from your API keys that authenticate Stripe API requests.

The client secret should still be handled carefully because it can complete the charge. Don’t log it, embed it in URLs, or expose it to anyone but the customer.

Use stripe.confirmKlarnaPayment to handle the redirect away from your page and to complete the payment. Add a return_url to this function to indicate where Stripe should redirect the user after they complete the payment on the Klarna website or mobile application.

On Klarna’s payments page, the customer selects among the payment options available in their market. See the table on the overview page for availability by market. You can’t limit or pre-select payment options on the Klarna payments page—deferring this choice to the consumer maximizes their opportunity to transact with you.

client.js
// Redirects away from the client
const {error} = await stripe.confirmKlarnaPayment(
  '{{PAYMENT_INTENT_CLIENT_SECRET}}',{
    return_url: 'https://example.com/checkout/complete',
  }
);
if (error) {
  // Inform the customer that there was an error.
}

When your customer submits a payment, Stripe redirects them to the return_url and includes the following URL query parameters. The return page can use them to get the status of the PaymentIntent so it can display the payment status to the customer.

When you specify the return_url, you can also append your own query parameters for use on the return page.

Parameter	Description
`payment_intent`	The unique identifier for the `PaymentIntent`.
`payment_intent_client_secret`	The client secret of the `PaymentIntent` object. For subscription integrations, this client_secret is also exposed on the `Invoice` object through `confirmation_secret`

When the customer is redirected back to your site, you can use the payment_intent_client_secret to query for the PaymentIntent and display the transaction status to your customer.

You can find details about the Klarna payment option the customer selected on the charge in the payment_method_details property. There are four possible values: pay_later, pay_with_financing, pay_now, and pay_in_installments. See our Klarna overview page for more information on these options.

You can also find the locale used to localize Klarna’s payments page under the payment_method_details property.

{
  "charges": {
    "data": [
      {
        "payment_method_details": {
          "klarna": {
            "payment_method_category": "pay_in_installments",
            "preferred_locale": "en-US"
          },
          "type": "klarna"
        },
        "id": "src_16xhynE8WzK49JbAs9M21jaR",
        "object": "source",
        "amount": 1099,
        "client_secret": "src_client_secret_UfwvW2WHpZ0s3QEn9g5x7waU",

Test Klarna integration

Below, we have specially selected test data for the currently supported customer countries. In a sandbox, Klarna approves or denies a transaction based on the supplied email address.

	Approved	Denied
Date of Birth	10-07-1970	03-05-1994
First Name	Test	John
Last Name	Person-au	snow
Street	Wharf St	Silverwater Rd
House number	4	1-5
Postal Code	4877	2128
City	Port Douglas	Silverwater
Region	QLD	NSW
Phone	+61473752244	+61473763254
Email	customer@email.au	customer+denied@email.au

For production testing, you can use an amount of 3500 in your local currency to test all Klarna payment options besides Financing. For example, if you want to test “Pay in 3” in Italy, you can use a transaction of 35.00 EUR.

Two-step authentication

Any six digit number is a valid two-step authentication code. Use 999999 for authentication to fail.

Repayment method

Inside the Klarna flow, you can use the following test values to try various repayment types:

Type	Value
Direct Debit	DE11520513735120710131
Bank transfer	Demo Bank
Credit Card	Number: 4111 1111 1111 1111 CVV: 123 Expiration: any valid date in the future
Debit Card	Number: 4012 8888 8888 1881 CVV: 123 Expiration: any valid date in the future

OptionalSeparate authorization and capture

OptionalHandle the Klarna redirect manually

OptionalHandle post-payment events

OptionalCustomize the Klarna payment page

OptionalAdd line items to the PaymentIntent

OptionalDisplay payment method messaging on your website

Failed payments

Klarna takes into account multiple factors when deciding to accept or decline a transaction (for example, length of time buyer has been using Klarna, outstanding amount customer has to repay, value of the current order).

When the customer selects a deferred payment method, Klarna performs a risk assessment before accepting the transaction. Klarna might decline the transaction due to unsatisfactory risk assessment result, the transaction amount involved, or the customer having a large outstanding debt. As such, we recommend that you present additional payment options such as card in your checkout flow. In these cases, the PaymentMethod is detached and the PaymentIntent object’s status automatically transitions to requires_payment_method.

Customers are expected to complete the payment within 48 hours after they’re redirected to the Klarna site. If no action is taken after 48 hours, the PaymentMethod is detached and the PaymentIntent object’s status automatically transitions from requires_action to requires_payment_method.

In these cases, inform your customer to try again with a different payment option presented in your checkout flow.

Klarna rate limits

API requests to Klarna are subject to additional rate limits beyond Stripe’s API-wide rate limits. These limits can differ depending on the shape of the API requests that you make. In general, if you make more than around 360 requests per minute, you may see some rate limiting in the form of responses with HTTP status code 400 or 402. Please contact us for more details if you’re concerned that your usage may reach these levels, as Klarna may be able to increase these limits on a case by case basis.

Error messaging

Failed Klarna payments normally return one of the following failure codes. These codes show in the last_payment_error API object.

Caution

Before the 2023-08-16 API version, every Klarna error reported as payment_intent_authentication_failure. Make sure your API version is up to date to see the detailed errors listed below.

Failure code	Explanation
payment_method_customer_decline	The customer cancelled the checkout on Klarna’s page
payment_method_provider_decline	Klarna declined the customer’s payment
payment_intent_payment_attempt_expired	The customer never completed the checkout on Klarna’s page, and the payment session has expired
payment_method_not_available	An unexpected error occurred when trying to use Klarna