A PSP (Payment Service Provider) is a technical payment processing company that handles online transactions between customers, online stores, banks, and payment methods. PSPs act as the connection layer between an e-commerce platform and payment options such as credit cards, PayPal, Klarna, Apple Pay, bank transfers, or SEPA payments.
Instead of integrating each payment method individually, merchants connect to a single PSP platform that provides access to multiple payment solutions through one interface. This simplifies development and payment management significantly.
Modern PSPs do far more than just transfer payments. They also provide fraud detection, 3D Secure authentication, recurring payment systems, refunds, currency conversion, analytics dashboards, and subscription billing features.
Popular PSPs include Stripe, Mollie, Adyen, Payone, Unzer, and Klarna. The right provider depends on the business model, target market, supported payment methods, and technical requirements. Some PSPs focus on developer-friendly APIs, while others specialize in enterprise-level commerce or simplified integrations.
Most payment service providers offer APIs, plugins, or SDKs for systems like WooCommerce, Shopware, Magento, or Shopify, making them a core component of modern e-commerce infrastructure.