ACH File Converter

ACH Reversal Generator

Create a reviewable reversal file from the original approved ACH instructions.

Reversals are permitted only for specific circumstances and timeframes. Confirm eligibility with your bank before transmitting the generated file.

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Source ACH/NACHA file

Approve and validate the reversal

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When a reversal may be appropriate

Reversals address defined erroneous-entry situations, not ordinary payment cancellation or dispute handling. Confirm the reason, timing, and authorization under current rules and ODFI procedures.

How the original entry is reversed

The new file changes the credit or debit direction through the appropriate transaction code, retains identifying context needed for review, assigns new traces, and rebuilds all controls.

Controls before releasing the file

  • Document the qualifying error and approval.
  • Confirm the affected entries and amounts.
  • Check the reversal description and effective date.
  • Prevent both duplicate reversal and duplicate original transmission.

What the generator cannot decide

The tool cannot determine whether a reversal is legally or contractually permitted, whether funds remain available, or whether the ODFI will accept the file.

Questions about ACH reversals

Can I reverse any ACH payment?

No. Reversals are limited to defined erroneous-entry circumstances and timing requirements.

Does a reversal delete the original entry?

No. It creates a separate offsetting instruction with its own processing lifecycle.

Are new trace numbers created?

Yes. The reversal output is a new file and receives rebuilt trace sequences and controls.

Which authoritative sources support this page?

Technical explanations are checked against these primary sources. Bank-specific requirements can be narrower than general format guidance.

  1. Nacha ACH File Details — Official record-field guidance, including Batch Header SEC codes and addenda capabilities.
  2. Nacha ACH File Overview — Official explanation of files, batches, entries, controls, and batch grouping.
  3. Nacha: How ACH Works — Official overview of ACH participants, consumer and corporate payments, and authorization responsibilities.
  4. Nacha Operating Rules Topics — Current rule changes and implementation topics published by Nacha.

Sources reviewed August 20, 2026. Nacha owns and maintains the linked materials.