A payment service provider (PSP) offers shops online services for accepting electronic payments by a variety of payment methods including credit card, bank-based payments such as direct debit, bank transfer, and real-time bank transfer based on online banking. Payment Service Provider  use a software as a service model and form a single payment gateway for their clients (merchants) to multiple payment methods.

PSP can connect to multiple acquiring banks, card, and payment networks. PSP will fully manage these technical connections, relationships with the external network, and bank accounts. This makes the merchant less dependent on financial institutions and free from the task of establishing these connections directly, especially when operating internationally.

PSP can offer risk management services for card and bank based payments, transaction payment matching, reporting, fund remittance and fraud protection in addition to multi-currency functionality and services. Some PSP provide services to process other payment systems including cash payments, wallets, prepaid cards or vouchers, and even paper or e-check processing.