A Payment Service Provider (PSP) is a company that enables businesses to accept electronic payments — including credit cards, debit cards, bank transfers, and alternative payment methods. PSPs act as intermediaries between the merchant, the card networks (Visa, Mastercard, etc.), and the acquiring and issuing banks. They provide the technical infrastructure to capture, authorise, and settle transactions, and they often bundle additional services such as fraud detection, reporting, currency conversion, and merchant onboarding. Well-known PSPs include companies like Adyen, Stripe, Worldpay, and Checkout.com.
The term PSP is often used interchangeably with payment gateway or payment processor, but there are meaningful distinctions. A PSP is typically a broader category — it may operate its own gateway and processing infrastructure, or it may aggregate multiple underlying processors and acquirers. Some PSPs hold acquiring licences and settle funds directly to merchants, while others rely on banking partners for settlement. The specific capabilities, geographic coverage, supported payment methods, and pricing models vary significantly between PSPs, which is why many businesses — particularly those operating across multiple markets — end up integrating with more than one.
Choosing a PSP is one of the most consequential infrastructure decisions a platform or merchant makes. The PSP directly affects authorisation rates (how many transactions are approved), settlement speed (how quickly the merchant receives funds), payment method coverage (which local methods are available in each market), and cost (interchange, scheme fees, and the PSP’s own margin). A PSP that performs well in one market may perform poorly in another. A PSP with strong card processing may lack support for the bank transfer methods that dominate in markets like Germany or the Netherlands.
This is where Shuttle Global’s PSP-neutral architecture becomes relevant. Rather than forcing platforms to choose a single PSP and live with its limitations, Shuttle provides a unified payment layer that connects to over 40 PSPs. A platform integrates once with Shuttle’s API, and Shuttle handles the routing, tokenization, and normalisation across all connected processors. If one PSP delivers better authorisation rates in a particular market, Shuttle can route transactions accordingly. If a platform wants to add a new PSP for a new region, there is no new integration to build. Shuttle’s Embedded Payments, Voice Checkout, and Payment Links all operate across this multi-PSP layer, so the platform’s products benefit from optimal PSP selection without any additional engineering work.