What Is Klarna

Klarna is a Swedish fintech giant that made “buy now, pay later” (BNPL) mainstream. Founded in 2005 by Sebastian Siemiatkowski, by 2026 it serves 150+ million users in 45 countries and processes transactions for 500,000+ merchants.

Unlike traditional credit cards, Klarna offers buyers three interest-free payment options: pay immediately, split into 4 installments, or pay in 30 days. The merchant gets paid immediately — Klarna takes on the risk.

Klarna vs Affirm: BNPL for E-commerce

BNPL (Buy Now, Pay Later) is the fastest-growing fintech segment. Klarna and Affirm are two leaders with different strategies. Klarna goes wide: 45 countries, 500K+ merchants. Affirm goes deep: US + Canada, but with high average order value and strong analytics. Which is better for your store?

Comparison Table

Where Klarna Wins

International Reach

45 countries vs two for Affirm. If your store sells to Europe, Australia, or Latin America — Klarna is the only choice. Affirm simply doesn’t work outside North America.

What Is Adyen

Adyen (pronounced “eye-den”) is a Dutch enterprise-grade payment platform serving Spotify, Uber, Microsoft, Booking.com, and thousands of global companies. Founded in 2006. Unlike Stripe, which grew from startups, Adyen targeted large businesses from day one.

Adyen isn’t just an acquirer. It’s the full stack: gateway + acquiring + risk management + payment analytics. All on a single platform, without bouncing between providers.

Key Features

Single Platform

Adyen’s main differentiator. Instead of assembling a zoo of payment gateway, acquirer, fraud provider, and analytics tool, Adyen provides everything in one contract. This reduces operational costs by 20-30% according to the company.

Choosing a payment system is one of the most important technical decisions for a business. It affects checkout conversion, payout speed, tax risks, and operational costs. A mistake at this stage can cost thousands of dollars in lost revenue.

Let’s break down three payment acceptance models and the selection criteria.

Three Payment Acceptance Models

1. Payment Gateway

You integrate a payment gateway directly. Money flows from the buyer through the gateway to your bank account. You’re responsible for everything: taxes, refunds, security, payer support.

Stripe and Square are the two biggest names in payment processing. Both were founded in the late 2000s, both became public companies with multi-billion-dollar market caps. But they have fundamentally different philosophies: Stripe is for developers and online business, Square is for retail and offline.

Philosophy and Positioning

Stripe is a platform for the internet economy. Created by developers for developers: clean API, excellent documentation, full programmability. If your business is a website or an app, Stripe gives you maximum flexibility in how the payment process looks and works.

Square is an American fintech company that grew from a tiny card reader for iPhone into an ecosystem of hardware, software, and banking services. Today, Square serves millions of small businesses from coffee shops to online stores, offering everything from terminals to lending and checking accounts.

The Square Ecosystem

Square is not just a payment gateway. It’s a full operating system for business:

Offline payments: proprietary POS terminals (Square Reader, Square Terminal, Square Register) accept cards, Apple Pay, Google Pay. Fixed-rate commission with no hidden fees.

Gumroad is a pioneer of the Merchant of Record model for content creators. You upload a digital product, set a price — everything else (payment processing, taxes, VAT, refunds, file delivery) is handled by the platform. No business registration or payment gateway integrations needed.

How Gumroad Works

The model couldn’t be simpler: create a product page, upload files, set a price. Gumroad processes payments, calculates and pays taxes (including VAT for EU), delivers the product to the buyer, and handles refunds. You receive payouts to your bank account or PayPal.