A technique is provided for automatically converting checks to ACH debits. The process is a two-part process in which the MICR line in a check is read at the point the check is presented and a decision is made if the check can be converted to an ACH debit. The decision is made by applying various rules. If the system is unable to convert the check to an ACH debit, then the check is processed as a normal check. If a decision is made that the check can be processed as an ACH debit, then the MICR line is parsed for the financial institution which issues the check to create the ACH debit.