ACH return codes, R01 to R85.

Sent back by the RDFI — or by the ACH Operator, a Gateway or a federal agency — when an entry can’t or shouldn’t post.

Sent by the ODFI to refuse a return it believes was improper.

Sent by the RDFI to dispute a dishonor.

R90 takes effect on Friday, March 17, 2028. Adopted by Nacha with effect from March 17, 2028, and not used before then: until that date a return for OFAC reasons uses R16. Confirm the details in the Rules once it is in force.

• Most returns must be available to the ODFI by opening of business on the second banking day after the settlement date of the original entry.
• Unauthorized consumer debits and a few check-conversion codes (R05, R07, R10, R11, R33, R37, R38, R51, R52, R53) may come back within 60 calendar days: the extended return window.
• The extended returns R05, R07, R10, R11, R37, R51, R53 need the Receiver’s Written Statement of Unauthorized Debit, and since October 1, 2024 the RDFI must send one by the opening of the sixth banking day after it finishes reviewing the statement. Business accounts have no extended window: R29 within 2 banking days, or R31 later with the ODFI’s agreement.
• R06 has no fixed window: the ODFI may ask for a return for any reason, and since April 1, 2025 the RDFI must answer within 10 banking days.
• The ACH Operator itself returns entries it can’t process (R13, R18, R28, R30, R32, and R19 and R25–R27, which an RDFI may use too) at its next file delivery.
• Dishonored returns run 5 banking days from the return’s settlement date; contested dishonored returns 2 banking days from the dishonored return’s.

Banking days follow the Federal Reserve calendar — see the bank holidays by year — and the ACH date calculator turns a code and a settlement date into a deadline.

Nacha monitors each Originator’s returns as a share of its debit entries. Above these levels it can start an inquiry with the ODFI; check the current Rules for how the rates are measured.

A return is the original entry detail record sent back with a return transaction code and an addenda record of type 99. The reason code is in positions 4–6 of that addenda, next to the original entry’s trace number (positions 7–21). Each code’s page shows the whole record.

To read a return file record by record, open the file in NACHA Navigator, a free sister site that parses NACHA files in your browser without uploading them.

• Notification of Change codes (C01–C14): corrections an RDFI sends instead of returning an entry.
• SEC codes: which codes allow which returns (PPD, CCD, WEB, TEL…).