ACH Standard Entry Class code

IAT SEC code: International ACH Transaction

Entry involving a financial agency outside the United States.

What IAT is for

Any ACH debit or credit that is part of a payment transaction involving a financial agency’s office outside the US — a payroll credit funded from abroad, for example.
Seven mandatory addenda records (types 10–16: names, addresses, the foreign institutions) plus optional remittance (17) and correspondent bank (18) records.

Consumer or business accounts, when the payment involves a financial institution outside the United States.

Authorization

The authorization rules of the underlying payment apply (consumer or business), plus the US sanctions screening that IAT entries exist to support.

A summary in general terms: the Nacha Operating Rules set the exact requirements, and Regulation E adds its own for consumer accounts.

Debits, credits and addenda

Debits and credits.

Addenda on a forward entry: type 10–18, 7 to 14 per entry. Returns (addenda type 99) and Notifications of Change (type 98) follow their own layouts whatever the SEC code.

Returns

IAT has its own return codes, R80–R84, and R85 for an outbound international payment sent with a domestic SEC code. IAT entries are not eligible for Same Day ACH.

Common mix-ups

An international payment sent as PPD or CCD instead of IAT can be returned R85, or answered with the NOC C14.

Where IAT sits in a NACHA file

The SEC code is a batch-level field: positions 51–53 of the Company/Batch Header record (type 5), so every entry in the batch shares it, and a file that mixes SEC codes puts them in separate batches. The batch header also carries the Company Name, Company Identification and Company Entry Description that Receivers see on their statements.

To read a IAT batch 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 IAT from code or an AI agent

REST · GET · no key

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

MCP · tools/call · lookup_payment_code

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

Response (JSON)

{
  "code": "IAT",
  "set": "ach-sec",
  "found": true,
  "matches": [
    {
      "set": "ach-sec",
      "code": "IAT",
      "name": "International ACH Transaction",
      "description": "Entry involving a financial agency outside the United States.",
      "details": {
        "direction": "both",
        "addendaTypes": "10, 11, 12, 13, 14, 15, 16, 17, 18",
        "minAddenda": 7,
        "maxAddenda": 14
      }
    }
  ]
}

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 Three (Standard Entry Class codes). The code’s name 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.