Why Every E-Commerce Site Is Adding Klarna and How to Integrate It
7 min read
Klarna Is Everywhere Now
If you’ve bought anything online in Europe recently, you’ve probably seen Klarna at checkout. What started as a Swedish buy-now-pay-later (BNPL) service has become one of the most requested payment methods across European e-commerce, and increasingly in Switzerland too.
The numbers tell the story: as of Q3 2025, Klarna has over 114 million active users globally, processes around 3.4 million transactions per day, and partners with 850,000+ merchants. In markets like Germany, Sweden, and the Netherlands, not offering Klarna is like not accepting credit cards a decade ago: customers expect it.
I’ve been integrating Klarna into client projects with growing frequency over the past year. Here’s why it’s taken off and what you need to know to add it to your platform.
Why Merchants Are Adopting Klarna
It increases average order value
This is the main reason merchants care. Klarna’s “Pay in 3” and “Pay Later” options let customers split purchases into installments or defer payment by 30 days. The psychological effect is real: when the displayed price at checkout drops from CHF 300 to “3x CHF 100,” customers are more likely to complete the purchase and more willing to add items to the cart.
Merchants I’ve worked with have seen 20-40% increases in average order value after adding Klarna. The uplift is most pronounced for products in the CHF 100-500 range, expensive enough that splitting the payment matters, but not so expensive that financing concerns dominate.
It reduces checkout abandonment
Checkout abandonment is the silent killer of e-commerce revenue. A significant percentage of abandoned carts happen at the payment step: the customer sees the total, hesitates, and leaves. Klarna’s flexible payment options give them a reason to stay.
The effect isn’t just about installments. Klarna’s hosted checkout is fast, familiar to returning Klarna users (their details are pre-filled), and handles the payment UX for you. Less friction, fewer drop-offs.
Klarna absorbs the risk
Here’s the part that surprises merchants who haven’t looked into it: you get paid immediately and in full. Klarna pays you the full order amount upfront, then collects from the customer over time. If the customer defaults, that’s Klarna’s problem, not yours.
You pay a transaction fee for this (typically 2-4% depending on your volume and region), but you eliminate credit risk entirely and improve your cash flow compared to traditional invoicing.
The customer base is already there
Klarna has built a consumer app with millions of active users who browse products, track orders, and manage payments through Klarna directly. Being a Klarna merchant means your products can appear in Klarna’s ecosystem, essentially a free discovery channel.
Klarna in Switzerland
Switzerland has been slower to adopt BNPL compared to Germany or the Nordics, but the trend is accelerating. Klarna launched full support for Swiss merchants and CHF transactions, and consumer awareness is growing, especially among younger demographics.
For Swiss e-commerce specifically, Klarna fills a gap in the payment mix. The typical Swiss checkout offers Stripe (cards), Twint (mobile), and PostFinance (bank transfers). Adding Klarna covers the installment and invoice use cases that none of the others handle well.
If you’re targeting both Swiss and EU customers from the same platform, Klarna is especially valuable because it works across borders. One integration covers customers in Switzerland, Germany, Austria, France, and 20+ other markets.
How Klarna Integration Works
Klarna offers several integration approaches. The right one depends on your stack and how much control you want over the checkout experience.
Klarna Payments (Embedded)
This is the most common approach for custom-built platforms. You embed Klarna’s payment widget directly into your checkout page alongside your other payment methods (Stripe, Twint, etc.).
The flow:
- Create a session: When the customer reaches checkout, your server calls Klarna’s API to create a payment session with the order details (items, amounts, shipping).
- Render the widget: Klarna’s JavaScript SDK renders the payment options (Pay Now, Pay Later, Pay in 3) inside a container on your page.
- Authorize: When the customer selects Klarna and confirms, the widget returns an authorization token.
- Capture: Your server uses the authorization token to place the order with Klarna. You receive the funds.
This approach gives you full control over the checkout design and lets you treat Klarna as just another payment method in your abstraction layer.
Klarna Checkout (Hosted)
Klarna Checkout replaces your entire checkout flow with Klarna’s hosted experience. The customer enters their shipping address, selects a payment method (including non-Klarna options like cards), and completes the purchase, all within Klarna’s iframe.
This is faster to implement but gives you less control. It works well for simpler storefronts where you don’t need a heavily customized checkout.
Through a PSP (Stripe, Adyen, Mollie)
If you’re already using Stripe, Adyen, or Mollie as your payment service provider, you can enable Klarna as a payment method through their dashboard, often without writing any additional code. Stripe’s Payment Element, for example, can show Klarna automatically based on the customer’s location and the order amount.
This is the lowest-effort option but gives you the least control over the Klarna-specific experience.
Common Gotchas
Minimum and maximum amounts: Klarna has per-market limits on order values for each payment option. “Pay in 3” might require a minimum of CHF 35 and a maximum of CHF 3,000. Your checkout needs to show or hide Klarna options based on the cart total.
Address requirements: Klarna needs the customer’s billing address to make a credit decision. If your checkout collects shipping address first, you need to also collect billing address before showing Klarna options.
Currency and market: Klarna sessions are market-specific. A session created for Switzerland (CHF) can’t be used for a German customer (EUR). If your platform serves multiple markets, you need to create the session with the correct locale and currency.
Testing: Klarna’s sandbox environment uses test credentials and fake personal data. The test flows are well-documented but behave slightly differently from production (approval rates, for example). Always do a real-money test transaction before going live.
Settlement reporting: Klarna’s settlement reports have a different format from Stripe or other providers. Build your reconciliation process to handle Klarna’s specific report structure, or you’ll be doing manual matching.
Should You Add Klarna?
If you’re running a B2C e-commerce site in Europe with products in the CHF 50-2,000 range, adding Klarna is close to a no-brainer. The conversion uplift typically pays for the transaction fees within the first month.
If you’re B2B, selling low-value digital goods, or operating in a market where Klarna has low consumer adoption, the ROI is less clear. Check Klarna’s market coverage for your specific customer base before committing.
The integration effort is moderate, a few days for the Klarna Payments approach, less if you’re going through an existing PSP. The hardest part isn’t the API integration; it’s updating your order management flow to handle Klarna’s capture and refund model correctly.
Key Takeaways
- Klarna is becoming a checkout expectation in European e-commerce, not a nice-to-have
- You get paid immediately: Klarna takes the credit risk, not you
- Average order value increases are the primary business case, typically 20-40%
- Integrate through your payment abstraction layer: treat Klarna like any other payment method
- Handle partial captures: your order management system needs to support per-shipment capturing
- Test with real transactions before launch, sandbox behavior doesn’t perfectly match production
Need help adding Klarna to your e-commerce platform? Get in touch or visit tedbin.com.