Abstract: A method of processing a check in an electronic funds transfer system, includes storing financial information, such as a routing number and an account number, obtained from at least one financial institution at predetermined times per year, in a database; receiving check information from a first financial institution; comparing the check information with the stored financial information in the database; modifying the check information to correspond with stored financial information from the first financial institution when the check information does not match the stored financial information; and processing the modified check information through an ACH system. The modifying step includes automatically changing a routing number and/or an account number to make said check information ACH compliant.