Who Klarna is
Klarna is a Swedish payments company, founded in Stockholm in 2005. At the checkout, shoppers choose to pay in full, in 30 days, in three or four instalments, or with financing, depending on their country and the order. Merchants are paid upfront and in full, and Klarna takes the credit and fraud risk.
Klarna holds a full banking licence, secured in 2017, and Klarna Group plc has been listed on the New York Stock Exchange since September 2025. Online shops offer it directly or through their payment provider, and it is the pay later method our checkout module connects to.
What it does in your platform
Checkout
Adds pay later and instalments to every merchant's hosted checkout. Klarna decides which options a buyer gets and carries the credit risk; the module creates the order, captures it through Klarna's Order Management and books it in the ledger.
How the connection works
One connector in the checkout module talks to Klarna's payments and order management APIs. The checkout page only receives a client token for this purchase; Klarna's credentials stay in the platform's secrets.
A session is opened
When the buyer reaches the checkout, the module opens a Klarna payment session with the order lines and gets a client token back.
Klarna shows the options
Klarna's JavaScript SDK loads the widget with that token and shows the options that fit the buyer's country and basket.
The buyer authorises
The Klarna window opens, the buyer logs in and picks how to pay, and Klarna runs its checks. The page receives an authorisation token.
The order is created
The module sends the authorisation token to Klarna and creates the order, which closes the payment session.
Captured on shipment
When the merchant ships, the module captures the order through Klarna's Order Management API, in full or in part.
Refunds and records
Refunds go through the same API, and every order, capture and refund shows up in the backoffice and the ledger.
Next to other payment methods
Klarna is the checkout's pay later method, next to cards, wallets, bank payments and stablecoins. Buyers pay with the method they trust, and each method runs through the provider that offers it.
Klarna also works through payment providers, among them Stripe, Adyen and Worldpay. The checkout routes to your existing provider contracts first, so if you already offer Klarna through one, we start from there. Changing the route later does not change your apps or your merchants' integration.
When Klarna fits best
A strong fit when
- Your merchants sell larger baskets that buyers like to spread over time.
- You want pay later without carrying the credit risk: Klarna takes it, and merchants are paid upfront.
- Your buyers are in the countries where Klarna offers its options.
Also worth a look
- Your current payment provider, kept as the route to Klarna if you already offer it there.
- Cards and wallets, for buyers who would rather pay at once.
How we get you live
The contract
We help you get your Klarna account and contract in place, directly or through a payment provider you already use.
The options
We set up with you the markets, currencies and order details Klarna needs, and when orders are captured for each kind of merchant.
The keys
The API credentials go into your platform's secrets and nowhere else; the checkout page only ever sees a client token.
A full test run
The whole flow runs in Klarna's playground environment, with Klarna's sample buyers, before your first real order.