A point-of-sale terminal includes a card interface, and is configured to receive a plurality of pre-authorization requests, each comprising an authorization and further comprising an account number received from the card interface. The terminal is further configured, in response to each said pre-authorization request, to locate in a pre-authorization database a database record associated with the respective account number, confirm that the respective authorization amount is not greater than an offline authorization threshold, generate an authorization confirmation message comprising the respective account number and the respective authorization amount, and save the authorization confirmation message in a clearing database. The terminal is further configured to generate a clearing payload comprising the plurality of saved authorization confirmation messages, and transmit the clearing payload over a computer network.