ACH Notification of Change code
C13 NOC code: Addenda Format Error
An RDFI sends C13 instead of returning an entry it could post but that carried outdated or wrong information. Corrected data: No fixed layout: the correction concerns how the addenda record was formatted.
What C13 means
C13 is the change code Addenda Format Error
. The entry it answers was posted (or, for a prenotification, accepted); the NOC tells the Originator what to correct before the next one.
- The entry posted, but the information in its addenda record was unclear or formatted incorrectly — a CCD addenda that follows neither ANSI ASC X12 nor a banking convention Nacha endorses, for example.
What to update, and by when
Fix the addenda formatting for future entries; read the NOC for what the RDFI found, since C13 has no fixed Corrected Data layout.
The Rules give the Originator six banking days from receiving the NOC information, or until its next entry to the account, whichever is later. NOCs carry no money: the entry they answer settled normally.
The RDFI transmits the NOC within 2 banking days of the settlement date of the original entry; the Originator makes the change within 6 banking days of receiving the NOC information or before its next entry, whichever is later.
Worked example
For an entry that settled on Wednesday, November 25, 2026, the day before Thanksgiving: the RDFI must transmit the NOC by Monday, November 30, 2026.
How C13 appears in a NACHA file
A NOC is a zero-dollar entry in a batch with SEC code COR. Its entry detail record carries a return-type transaction code (21, 26, 31 or 36) and one addenda record of type 98:
| Positions | Field | In a C13 NOC |
|---|---|---|
| 1 | Record Type Code | 7 (addenda) |
| 2–3 | Addenda Type Code | 98 (Notification of Change) |
| 4–6 | Change Code | C13 |
| 7–21 | Original Entry Trace Number | Trace number of the entry being corrected |
| 22–27 | Reserved | Blank |
| 28–35 | Original Receiving DFI Identification | First 8 digits of the original entry’s RDFI routing number |
| 36–64 | Corrected Data | No fixed layout: the correction concerns how the addenda record was formatted |
| 65–79 | Reserved | Blank |
| 80–94 | Trace Number | The NOC entry’s own trace number |
To read a NOC file record by record, open the file in NACHA Navigator, a free sister site that parses NACHA files in your browser without uploading them.
Look up C13 from code or an AI agent
curl -s 'https://payopskit.com/api/v1/codes/C13?set=ach-noc'{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "lookup_payment_code",
"arguments": {
"code": "C13",
"set": "ach-noc"
}
}
}{
"code": "C13",
"set": "ach-noc",
"found": true,
"matches": [
{
"set": "ach-noc",
"code": "C13",
"name": "Addenda Format Error",
"description": "Notification of Change. Corrected data: No fixed layout: the correction concerns how the addenda record was formatted.",
"details": {
"refused": false,
"retired": false,
"correctedData": "No fixed layout: the correction concerns how the addenda record was formatted",
"timeframe": "The RDFI transmits the NOC within 2 banking days of the settlement date of the original entry; the Originator makes the change within 6 banking days of receiving the NOC information or before its next entry, whichever is later",
"timeframeKind": "banking-days",
"timeframeDays": 2,
"caveat": null
}
}
]
}The MCP server is at /mcp (Streamable HTTP, no key); the API and MCP docs show how to connect Claude, Cursor or VS Code.
Source: Nacha Operating Rules, Appendix Five (Notification of Change). The code’s title is the Rules’ own; the rest is this site’s plain-language summary, informational and not a substitute for the Rules or your ODFI agreement.