ACH return reason code
R80 return code: IAT Entry Coding Error
An IAT entry has errors in its IAT-specific fields.
What R80 means
R80 is the return reason code IAT Entry Coding Error
. An IAT entry has errors in its IAT-specific fields.
IAT entries.
It is sent by the Gateway or RDFI as a return entry: the original entry goes back to the ODFI with an addenda record carrying R80, and the ODFI passes the return on to the Originator.
Typical causes
- An IAT entry has errors in its IAT-specific fields or addenda.
Return timeframe
Available to the ODFI by opening of business on the 2nd banking day after the settlement date of the original entry.
Banking days are the Federal Reserve’s business days: weekends and Fed holidays don’t count, so a holiday in the window pushes the deadline out by a day.
Worked example
For an entry that settled on Wednesday, November 25, 2026, the day before Thanksgiving: must be available to the ODFI by opening of business on Monday, November 30, 2026.
What the Originator can do next
- Check the IAT addenda (the foreign receiving institution’s identification, names and addresses) with your ODFI and its Gateway before sending again.
How R80 appears in a NACHA file
A return is the original entry detail record (type 6) sent back with a return transaction code — 21 or 26 for a checking account, 31 or 36 for savings (21 and 31 return a credit, 26 and 36 a debit) — the original amount, and an addenda record of type 99 that carries the reason. The batch keeps the original entry’s SEC code.
| Positions | Field | In an R80 return |
|---|---|---|
| 1 | Record Type Code | 7 (addenda) |
| 2–3 | Addenda Type Code | 99 (return) |
| 4–6 | Return Reason Code | R80 |
| 7–21 | Original Entry Trace Number | Trace number of the entry being returned |
| 22–27 | Date of Death | YYMMDD for R14 and R15; blank otherwise |
| 28–35 | Original Receiving DFI Identification | First 8 digits of the original entry’s RDFI routing number |
| 36–79 | Addenda Information | Free text from the RDFI |
| 80–94 | Trace Number | The return entry’s own trace number |
Returns of IAT entries use the IAT version of the return addenda; check its layout in the Rules.
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.
Look up R80 from code or an AI agent
The code table on this page is the one behind the REST API and the MCP server, so a script or an AI agent gets the same answer as JSON. No key and no account.
curl -s 'https://payopskit.com/api/v1/codes/R80?set=ach-return'{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "lookup_payment_code",
"arguments": {
"code": "R80",
"set": "ach-return"
}
}
}{
"code": "R80",
"set": "ach-return",
"found": true,
"matches": [
{
"set": "ach-return",
"code": "R80",
"name": "IAT Entry Coding Error",
"description": "An IAT entry has errors in its IAT-specific fields.",
"details": {
"category": "return",
"timeframe": "Available to the ODFI by opening of business on the 2nd banking day after the settlement date of the original entry",
"timeframeKind": "banking-days",
"timeframeDays": 2,
"timeframeFrom": "original-settlement",
"account": "any",
"accountNote": "IAT entries.",
"writtenStatement": false,
"initiatedBy": "Gateway or RDFI",
"note": "IAT only",
"effectiveFrom": null,
"upcomingChange": null,
"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.
The deadline for a settlement date: GET /api/v1/ach/return-deadline?settlement_date=2026-11-25&code=R80 or the MCP tool ach_return_deadline.
Source: Nacha Operating Rules, Appendix Four (Return Entries). The code’s title is the Rules’ own; the rest is this site’s plain-language summary. It is informational and not a substitute for the Rules, your ACH Operator’s schedule or your ODFI agreement.