Klarna Express Checkout

Klarna buy-now-pay-later is a three-call sequence on the /express/klarna/… paths. Call them in order:

1. Start — create the Klarna session and get the client_token
2. Authorize — confirm the buyer’s authorization
3. Complete Order — place the order

Between Start and Authorize the buyer approves the payment in the Klarna Payments widget, which returns an authorization_token. Nothing is charged until Complete Order.

​​ Checking availability

Klarna is enabled per merchant, and most merchants do not have it. Any cart response lists what the merchant supports:

"payment_method_options": [
  { "type": "CreditCard", "wallet": "user" },
  { "type": "Klarna", "wallet": "klarna" }
]

If no "type": "Klarna" entry is present, do not offer Klarna — calling these endpoints returns 404 GatewayNotFound. The examples on these pages use the sandbox merchant for shape; check payment_method_options for the merchant you are actually integrating rather than assuming Klarna is available.