Integration Checklist

Guidance on enabling Klarna using Stripe APIs and the different integration path available: Hosted Payment Page or building a custom payment selector form with Klarna APIs.

Integration Checklist

To ensure a robust, seamless, and customer-friendly Klarna integration through Stripe, it is essential to follow a set of best practices. This checklist will help you finalize your Klarna setup using Stripe APIs and prepare for go-live with full functionality and compliance.

Address and phone validations

Make sure to validate all addresses and phone numbers before sharing them with Stripe. Rejections due to mismatched or incorrect addresses late in the process can negatively affect acceptance rates, so ensuring these are correct early on is critical.

Billing country and address

Billing country and billing email are always required for Klarna transactions. Make sure to provide the correct information for all payment sessions to avoid the transactions being rejected.

Set up branding in the Stripe dashboard

Upload your logo and brand name.

Benefit: Klarna will reflect your brand across touchpoints with the consumer, improving recognition and trust.

Include `line_items` in the payload

Add all available order details to the line items in your API requests to Stripe.

Benefit: Enables enhanced fraud detection, enriched post purchase experience with detailed receipts.

Ensure consistency across your systems and communications with customer by sharing your customer-facing order ID ( order.references.merchantReference ).

Benefit: The information is displayed across all touch points between the customer and Klarna, including Klarna app and emails. It is also a key data point to support your reconciliation process and dispute management.

Send Supplementary Purchase Data

This data could be shared via payment_method_options.klarna.supplementary_purchase_data , which is a serialized JSON object that follows Klarna’s Interoperability Data Schema or via structured objects in Stripe API.

Include in relevant API calls to provide session and customer context.

Benefit: Enhances session continuity, allowing for greater personalization and improved conversion rates. Additionally, will support processing for specific MCCs.

Forward the interoperability token

In an Advanced integration, you will receive an interoperability_token from Klarna when the customer interacts with services powered by WebSDK, such as Klarna On-site Messaging, Sign in with Klarna, or Express Checkout.

If interoperability_token is available, include it in your API requests to Stripe.

Benefit: Links customer context across touch points for a smoother experience.

Testing

We recommend testing the integration before launching Klarna’s payment method in live mode. When in Stripe test mode, confirm that all information requested from the customer is passed through to Klarna at checkout. You can do that by placing sample orders in the test environment and validating the information displayed on the Klarna hosted payment page.

Check out the Stripe guidelines for information on how to best leverage test mode to verify your integration.

Optimize Klarna transactions

Integration Checklist