An ACH entry begins when a Receiver authorizes an Originator to issue an ACH debit or credit to an account. An Originator can be a person, your local cable company, charity or your employer. Depending on the ACH transaction, the Originator must receive written (ARC, POP, PPD), verbal (TEL), or electronic (WEB) authorization from the Receiver. Once authorization is received, the Originator creates an ACH entry to be transmitted to an Originating Depository Financial Institution (ODFI), who can be any financial institution who offers ACH origination.

This ACH entry is then sent to an ACH Operator (the FED or EPN) and is passed on to the Receiving Depository Financial Institution (RDFI), where the Receiver's account is issued either a credit or debit depending on the ACH transaction.