Optimize Klarna transactions

How Partners can improve Klarna approval rates and reduce false declines by sharing complete and accurate purchase data — line items, purchase reference, customer details, and shipping information — at every stage of the transaction lifecycle.

Sharing complete and accurate data with every payment is one of the most effective actions Partners can take to improve their Klarna integration. When Partners provide detailed information about products, customers, and shipping to the Acquiring Partner, Klarna can make more accurate authorization decisions — leading to higher approval rates, fewer false declines, and a better experience for customers.

Providing complete purchase data — including line items, purchase reference, customer details, and shipping information — is a contractual requirement under the Klarna Network Rules. Beyond compliance, providing complete data is one of the highest-impact actions Partners can take to improve authorization rates, reduce disputes, and deliver a better customer experience.

What is purchase data

Purchase data is the set of information Partners provide alongside each payment request to the Acquiring Partner. The Acquiring Partner uses this data to complete the payment with Klarna on behalf of Partners. It includes:

Line items — per-product details such as name, quantity, price, tax, images, and URLs
Purchase reference — the customer-facing transaction identifier
Customer details — name, email, phone, address
Shipping information — delivery address, carrier, shipping method, and recipient details

Partners provide this data in the Acquiring Partner's payment API — not directly to Klarna. The Acquiring Partner is responsible for forwarding it to Klarna in the correct format. For data the Acquiring Partner's API doesn't support structurally (for example, travel reservations or customer purchase history), Klarna provides a separate passthrough mechanism called klarna_network_data. See Share purchase data through your Acquiring Partner for both mechanisms.

supplementary_purchase_data is the internal Klarna API parameter the Acquiring Partner populates when calling Klarna. Partners do not use this field name directly — Partners provide data through the Acquiring Partner's own API fields. The Acquiring Partner handles the mapping.

How complete data improves conversion

Higher authorization rates and fewer false declines

Klarna's fraud assessment and underwriting models evaluate hundreds of signals in real time for every transaction. The more context Partners provide — product details, delivery information, customer identifiers — the more accurately Klarna can assess affordability and intent. This means more legitimate transactions get approved, while genuinely suspicious patterns are caught early.

More accurate data → smarter decisions → fewer false declines → higher conversion.

Faster dispute resolution

When a customer disputes a transaction, Klarna uses Partner data as part of the evidence package. If data is absent or inconsistent across the Payment Authorization, capture, and refund stages:

Klarna cannot provide itemized evidence to support the dispute
Refund mapping may fail, causing confusion for the customer and for Partners
Resolution time increases and outcomes can be less favorable

Klarna's automated dispute resolution works best when data is complete and consistent across all stages of the transaction lifecycle.

The value of each data category

Line items

Line item data provides critical transaction context that improves Payment Authorization outcomes and enables a better customer experience. While line items may not always be mandatory in API requests, sending complete and accurate line item data is mandatory for all Payment Authorizations.

Authorization benefits:

Enhanced fraud assessment — Detailed product information enables more accurate fraud detection and underwriting
Improved approval rates — Complete transaction context leads to higher authorization approval rates
Better customer verification — Product details help validate legitimate purchases and identify suspicious patterns
Regulatory compliance — Detailed line items support compliance requirements

Customer experience benefits:

Rich transaction displays — Clear product names, images, and prices in the Klarna app and email communications
Buy Again feature — Enables customers to repurchase items directly in the Klarna app
Reduced inquiries — Transparent transaction details reduce customer service contacts
Transaction tracking — Better visibility into what was purchased and when
Refund clarity — Clear mapping of refunded items to original purchases

Dispute resolution:

Consistent name and product_identifier values across all operations (Payment Authorization, capture, refund) are essential for dispute evidence integrity. When these values change between stages, Klarna cannot reliably match items to build a defense.

Purchase reference

The purchase reference is the customer-facing order identifier. It creates a consistent, traceable reference across Klarna touchpoints:

Improves traceability across systems and simplifies reconciliation
Appears in customer communications, making it easier for customers to identify their orders
Simplifies dispute resolution by linking Klarna transactions to Partners' internal order records
Ensures smoother customer communication and post-purchase experiences

Customer details

Providing customer data (name, email, phone, address) supports:

Better fraud assessment — Klarna can verify identity and assess creditworthiness more accurately
Personalized experiences — Enables tailored communication and offers through emails and push notifications
Fraud prevention — Cross-referencing customer data with behavioral signals helps detect account takeover and synthetic identity fraud
Reduced friction — Customer data pre-populates the Klarna purchase flow, reducing drop-off for both new and returning Klarna customers

Shipping information

Shipping details are critical for:

Fraud prevention — Billing and shipping addresses are a key fraud signal. Providing both helps Klarna detect suspicious patterns without blocking legitimate gifting or multi-address scenarios
Delivery transparency — Shipping carrier and method information supports proactive customer communication
Post-purchase experience — Customers can track deliveries directly through Klarna
Dispute evidence — Shipping details serve as proof of delivery intent and fulfillment

Impact across the order lifecycle

Stage	How Partner data helps
Checkout	Complete data enables faster Payment Authorization decisions, higher approval rates, and reduced false declines. Customers see a smooth payment experience.
Post-purchase	Line items with images and URLs power rich order views in the Klarna app, enable Buy Again, and reduce "what did I buy?" support contacts.
Capture & fulfillment	Consistent data between Payment Authorization and capture ensures seamless order processing. Shipping details support delivery tracking and proactive communication, helping reduce order-related support inquiries.
Refunds & returns	Matching line item data across operations enables accurate refund mapping. Customers see exactly which items were refunded and why.
Disputes	Complete, consistent data across all stages provides the evidence package Klarna needs to resolve disputes quickly and accurately.

Best practices

Send complete line items — including image_url and product_url — whenever data is available at checkout.
Use clear, customer-facing product names (for example, "Men's Denim Jeans - Blue, Size 32").
Include high-resolution product images (minimum 400×400px) using public HTTPS URLs.
Keep line items, purchase reference, and identifiers consistent across all operations (Payment Authorization, capture, refund).
Synchronize the order management system, checkout, and PSP integration layer so the same data flows consistently to the Acquiring Partner's API and on to Klarna.
Validate amounts, quantities, and tax values before submission — set total_tax_amount to 0 if no tax applies rather than omitting the field.

Don't

Use generic or internal product names like "Product 1" or "Item" — these weaken dispute evidence and degrade the customer experience.
Change names or identifiers between operations — inconsistencies cause refund mapping failures and break dispute evidence.
Send partial data at different stages — for example, including shipping details at Payment Authorization but omitting them at capture.
Mark shipping fees as products or products as fees — this confuses fraud assessment models and customer-facing displays.
Omit line items entirely — this misses authorization and experience benefits.

Data-driven quick wins

Action	Why it matters
Include detailed line items	Helps Klarna approve more transactions by improving fraud assessment accuracy while streamlining disputes, returns, and in-app order visibility.
Provide complete shipping and billing details	Enables Klarna to verify identities, detect fraud, and assess delivery risk more accurately — improving approval rates and reducing false positives and support requests.
Add purchase reference and customer identifiers	Creates a consistent, customer-facing reference that improves traceability across Klarna touchpoints, simplifies disputes, and ensures smoother customer communication.
Send data consistently across all operations	Ensures Klarna can build complete evidence packages for disputes, accurately map refunds, and maintain a coherent customer experience throughout the order lifecycle.

Better data = better decisions.

Every enriched data field helps Klarna's fraud assessment and underwriting models make faster and more accurate decisions — leading to more approvals, fewer false declines, and higher revenue for Partners.

How to send Klarna Network Data