A payment gateway is software that allows merchants to transmit transaction data from a customer's credit card, net banking, mobile payment, or digital wallet to an acquirer for authorization and settlement. The payment gateway checks that there are sufficient funds, that the details match correctly, and screens for fraudulent activity by communicating with card schemes and issuing banks. It then reports back the transaction response. Payment gateways allow merchants to perform real-time credit card authorizations from their website and allow customers to pay for online purchases with credit cards within seconds once the gateway obtains authorization from the credit card institutions.