Payment Gateway by Elisa | Jul 23, 2018 | The code that transmits a customer’s order to and from a merchant’s bank’s transaction-authorizing agent usually a MAP (merchant account provider). See also payment gateway provider. Don't miss out!Subscribe To The HMS NewsletterReceive top insights, news, and advice about payment processing, business funding, and more.Invalid email address Give it a try. You can unsubscribe at any time.Thanks for subscribing! Please check your email for further instructions.