ACH return reason code

R16 return code: Account Frozen/Entry Returned per OFAC Instruction

The account is frozen, or the entry is returned on OFAC instruction.

What R16 means

R16 is the return reason code Account Frozen/Entry Returned per OFAC Instruction. The account is frozen, or the entry is returned on OFAC instruction.

It is sent by the RDFI as a return entry: the original entry goes back to the ODFI with an addenda record carrying R16, and the ODFI passes the return on to the Originator.

Adopted change

From March 17, 2028 R16 is retitled "Account Frozen" and covers only accounts restricted by the RDFI or by legal action; returns the RDFI makes to meet its sanctions obligations (OFAC) move to the new code R90.

Typical causes

The account is frozen, by legal process or by the RDFI.
The entry was returned on the instruction of OFAC (the US Treasury’s Office of Foreign Assets Control).

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.

Try your own settlement date in the ACH date calculator

What the Originator can do next

Don’t reinitiate the entry; contact the Receiver another way.
If OFAC is cited, involve your compliance team.

How R16 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.

Return addenda record (type 99) with R16
Positions	Field	In an R16 return
1	Record Type Code	7 (addenda)
2–3	Addenda Type Code	99 (return)
4–6	Return Reason Code	`R16`
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

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 R16 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.

REST · GET · no key

curl -s 'https://payopskit.com/api/v1/codes/R16?set=ach-return'

MCP · tools/call · lookup_payment_code

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "lookup_payment_code",
    "arguments": {
      "code": "R16",
      "set": "ach-return"
    }
  }
}

Response (JSON)

{
  "code": "R16",
  "set": "ach-return",
  "found": true,
  "matches": [
    {
      "set": "ach-return",
      "code": "R16",
      "name": "Account Frozen/Entry Returned per OFAC Instruction",
      "description": "The account is frozen, or the entry is returned on OFAC instruction.",
      "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": null,
        "writtenStatement": false,
        "initiatedBy": "RDFI",
        "note": null,
        "effectiveFrom": null,
        "upcomingChange": "From March 17, 2028 R16 is retitled \"Account Frozen\" and covers only accounts restricted by the RDFI or by legal action; returns the RDFI makes to meet its sanctions obligations (OFAC) move to the new code R90.",
        "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=R16 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.