Public preview
Klarna supplementary purchase data Public preview
Learn how to provide Klarna-specific supplementary data for various industry verticals.
Available with preview header
You can use this public preview feature by including the version header 2025-11-17.preview or a later preview version header in your API request.
Supplementary purchase data adds context to a transaction to improve payment outcomes and customer support. Use it to send industry-specific details for verticals such as events, transportation, marketplaces, and insurance.
When to use supplementary purchase data
Use supplementary purchase data if you operate in a supported vertical and want to improve your payment outcomes with Klarna.
The supplementary data shared with Klarna supports these use cases:
- Post-purchase transparency : Provide detailed transaction breakdowns for your customers in the Klarna app, streamline disputes and returns, and reduce support requests.
- Higher acceptance rates : Historical data informs underwriting and can increase approvals for legitimate transactions.
- Enhanced fraud assessment : Detailed transaction insights support more effective fraud investigations, especially in high-risk segments.
- Risk exposure monitoring : Transaction data supports continuous monitoring and timely mitigation.
- Enhanced solution offerings : Based on historical behavior, Klarna can develop enhanced solutions for incentives and actions that benefit you and your customers.
Limitations
Keep these limits in mind:
- No fee changes : Passing supplementary purchase data doesn’t impact the fees you pay for Klarna transactions. Your pricing remains the same whether or not you provide this data.
- No validation feedback : Stripe and Klarna accept well-formed supplementary purchase data but don’t provide feedback on whether the specific data you send qualifies for improved outcomes.
Measure impact
Track your Klarna authorization rates over time in your payment analytics. After you implement supplementary purchase data, you might see more successful authorizations, though the impact varies based on your transaction patterns and the data you provide.
Availability
Supplementary purchase data is available exclusively for Klarna payments and supports the following industry verticals:
- Events (concerts, festivals, sports, conferences)
- Insurance (standalone insurance policies)
- Vouchers (gift cards, discount codes)
- Train transportation
- Bus transportation
- Ferry transportation
- Organized trips and tours
- Marketplace sellers
Travel and entertainment verticals
For lodging, car rentals, and air transportation with Klarna payments, see the travel and entertainment industry metadata documentation. Those verticals are shared with card payments, while the verticals on this page are Klarna-exclusive.
Send supplementary purchase data
You send Klarna-specific supplementary purchase data through the payment_method_options.klarna.supplementary_purchase_data parameter when you create, update, or confirm a PaymentIntent.
The supplementary_purchase_data hash contains an array of hashes for each vertical. Klarna processes all entries in these arrays for risk assessment. You can send multiple verticals in a single request.
Example: Create a PaymentIntent with voucher data
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Example: Create a PaymentIntent with multiple verticals
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Vertical data formats
The following tabs describe the hashes for the supported verticals:
Insurance data is sent through the payment_method_options.klarna.supplementary_purchase_data.insurances parameter. Each element in the array represents an individual insurance policy purchased as the primary product (not as an add-on to another service).
For the full list of fields and their formats, see the API reference (available with the 2025-11-17.preview or later preview version header).
Example: Creating a PaymentIntent with insurance data
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Update and remove supplementary purchase data
Use the update or confirm method to modify or remove supplementary purchase data.
Full replacement of verticals
When you update a vertical’s array, the new data completely replaces the existing data for that vertical. For example, if a PaymentIntent has 2 vouchers and you send an update with 1 voucher, the result is 1 voucher (not 3).
Create a PaymentIntent with 2 vouchers:
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Update the PaymentIntent with one voucher to replace the existing two vouchers:
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The PaymentIntent now has only one voucher.
Preserve existing data
Verticals excluded in an update request remain unchanged. For example, you can add train data without affecting existing vouchers or insurances:
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The PaymentIntent retains existing vouchers and insurances, and adds the train reservation.
Unset a specific vertical
To unset all data for a specific vertical while preserving other verticals, set the vertical to an empty string. This removes the vertical from the PaymentIntent.
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Unset all supplementary purchase data
To unset all supplementary purchase data from a PaymentIntent, set the entire supplementary_purchase_data parameter to an empty string:
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Testing
Test that your integration works correctly for your customers. Simulate API calls in a Stripe Sandbox with a sandbox key. Attach a payment method using the update method prior to confirming. For additional information, see Testing.