A merchant account is a type of bank account that allows businesses to accept payments in multiple ways, typically debit or credit cards. A merchant account is established under an agreement between an acceptor and a merchant acquiring bank for the settlement of payment card transactions. In some cases a payment processor, independent sales organization (ISO), or member service provider (MSP) is also a party to the merchant agreement. Whether a merchant enters into a merchant agreement directly with an acquiring bank or through an aggregator, the agreement contractually binds the merchant to obey the operating regulations established by the card associations.
Today a majority of credit card transactions are sent electronically to merchant processing banks for authorization, capture and deposit. Various methods exist for presenting a credit card sale to "the system." In all circumstances either the entire magnetic strip is read by a swipe through a credit card terminal/reader, a computer chip is read, or the credit card information is manually entered into a credit card terminal, a computer or website. The earliest methods, submitting credit card slips to a merchant processing bank by mail, or by accessing an Automated Response Unit (ARU) by telephone, are still in use today but have long been overshadowed by electronic devices. These early methods used two-part forms and a manual device for mechanically imprinting the embossed card number information onto the forms.
A credit card terminal is a stand-alone piece of electronic equipment that allows a merchant to swipe or key-enter a credit card's information as well as additional information required to process a credit card transaction. They may be connected to Point of Sale systems and typically have a keypad and network connection and may have a built-in printer.
An ARU (also known as a voice authorization, capture and deposit) allows the manual keyed entry and subsequent authorization of a credit card over a cellular or land-line telephone. With this method, a merchant typically imprints their customer's card with an imprinter to create a customer receipt and merchant copy, then process the transaction instantaneously over the phone.
A payment gateway is an e-commerce service that authorizes payments for e-businesses and online retailers. It is the equivalent of a physical POS (point-of-sale) terminal located in most retail outlets. A merchant account provider is typically a separate company from the payment gateway. Some merchant account providers have their own payment gateways but the majority of companies use 3rd party payment gateways. The gateway usually has 2 components: a) the virtual terminal that can allow for a merchant to securely login and key in credit card numbers or b) have the website's shopping-cart connect to the gateway via an API to allow for real time processing from the merchant's website.