ACH File Converter

ACH Notification of Change Analyzer

Read NOC codes and corrected account information.

1

Source ACH/NACHA file

Apply corrected account information

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Correction data contained in an NOC

The analyzer exposes the C code, corrected data field, original trace information, and related receiver context so the originator can update future instructions.

Common change-code categories

NOCs can report corrected account numbers, routing numbers, transaction codes, names, or other defined values. Interpret the specific C code before deciding which source field to update.

A controlled correction workflow

  • Match the original entry and receiver.
  • Record the C code and corrected value.
  • Update the authoritative source system.
  • Validate the next file and retain evidence of the change.

Why an NOC is different from a Return

An NOC communicates a correction for future entries; it does not by itself mean the original entry was returned. Settlement and exception teams should route the two record types differently.

Questions about ACH Notifications of Change

What is an ACH NOC?

A Notification of Change tells an originator that defined information should be corrected for future entries.

What does a C code identify?

It identifies the category of corrected data supplied in the addenda record.

Should I edit only the current file?

Usually the authoritative customer or payment system also needs the verified correction so future files do not repeat the issue.

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.