A Payment Gateway performs the following five core functions:
- Manages the merchant's switch configurations - defines an ID for each merchant payment configuration and communicates with payment switch using this ID.
- Manages the merchant's transaction roles - defines limitations for merchant's transactions. e.g the minimum and maximum amount a merchant can transact from a card in a day, restrict transactions from credit cards issued from a particular country etc.
- Manages the merchant's 3D secure configurations - Communicates with the switch and checks if the card holder is enrolled for the 3DS, the related MPI will then lookup in Card's directory services and the returns response to the payment gateway.
- Process Payments - makes request to the payment switch to process payments and receives results and returns to the customer.
- Sends payment receipts