Internet Check Acceptance. This is the type of check service provided on the Gateway. ICA uses the Automated Clearing House (ACH) to debit the consumer's account. The account information is entered in an online payment form, and no check is used (i.e., the check is still usable). The customer may or may not sign a payment form. In either case, the merchant needs a documented record of the customer's authorization to debit the account. ICA includes an electronic receipt (via e-mail). There is no check guarantee service with ICA. Typically used for mail order/telephone order (MO/TO) or e-commerce transactions, but may also be used for retail.