Payment Service Provider (PSP)

A Payment Service Provider (PSP) is a company that gives merchants a comprehensive solution for accepting electronic payments, combining Payment Gateway functionality, Payment Processor connectivity, and often Acquirer relationships under a single commercial arrangement. Rather than assembling separate gateway, processor, and acquiring relationships, a merchant using a PSP signs a single agreement and gains access to the full payment acceptance stack.

PSPs typically offer a range of payment methods beyond card payments: ACH (Automated Clearing House), Digital Wallets, Buy Now Pay Later (BNPL), Local Payment Methods (LPMs), and more. They handle PCI DSS compliance on the merchant's behalf for the portions of the transaction flow that pass through their systems, reducing the merchant's compliance burden. Many PSPs also provide fraud detection, reporting dashboards, and developer tools as part of their offering.

Well-known PSPs include Stripe, Adyen, Braintree, and PayPal. Each has different strengths: Stripe is renowned for developer experience and breadth of payment methods; Adyen is preferred by large enterprises for its global acquiring footprint and authorization rate optimization; Braintree (a PayPal subsidiary) is valued for its PayPal and Venmo integration.

The PSP model works well for businesses that want simplicity and speed. The tradeoff is dependency. A merchant that runs entirely through a single PSP is vulnerable to that provider's pricing decisions, service interruptions, and geographic limitations. Sophisticated merchants, particularly those operating across multiple countries or at high transaction volumes, often maintain relationships with multiple PSPs and use a Payments Orchestration Platform to route transactions across them, capturing the best authorization rates and pricing in each market without rebuilding their integration each time.