A Debit Authorization (828) is a transaction set used to request permission to debit a bank account or similar financial instrument. Typically sent by a creditor or their agent to a debtor’s financial institution, it communicates the intent to withdraw funds and may be submitted in response to a customer’s authorization agreement or as part of a recurring payment arrangement. The BAU (Beginning Segment for the Debit Authorization) segment establishes the core details of the request, while the DAD (Debit Authorization Detail) segment, which repeats as needed, specifies individual debit entries with associated payee or debtor information captured through NM1 (Individual or Organizational Name) segments.

For example, a utility company such as PowerCorp might send a 828 transaction to First National Bank to initiate monthly automatic debit payments from their customers’ accounts. The transaction would include a BAU segment with the authorization parameters, followed by multiple DAD loops—one for each customer—containing the customer’s name via NM1, their account reference via REF, and contact details via PER if disputes arise. The CTT (Transaction Totals) segment at the end summarizes the total number of debit entries being requested so the bank can reconcile the batch before processing.