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ISO 20022 reason code

MS03: Not specified reason (agent generated)

Refused by a bank; no reason given. MS03 is an ISO 20022 reason code used as a status reason and a return reason: you will see it in pain.002, pacs.004 and camt.053.

MS03 at a glance
CodeMS03
NameNot specified reason (agent generated)
ISO code listsExternalStatusReason1Code (status reason); ExternalReturnReason1Code (return reason)
WhereStsRsnInf/Rsn/Cd; RtrRsnInf/Rsn/Cd (pacs.004), TxDtls/RtrInf/Rsn/Cd (camt)

What MS03 means

A bank in the chain rejected or returned the payment without giving a reason, for example because of internal policy or because it may not disclose the reason.

Not to be confused with: MS03 is a bank refusing without a reason; MS02 is the customer. RR04 is a refusal a bank does explain, as regulatory.

A reason code always comes with a status or an action: on its own it says why, not what happened. In a status report look at the status next to it (RJCT means the payment will not be executed); on a statement the returned entry tells you the money has come back.

Where MS03 appears

MS03 belongs to two of the ISO 20022 reason code lists, so it can arrive in these places:

  • Status reason (ExternalStatusReason1Code): in a payment status report (pain.002 from a bank to its customer, pacs.002 between banks) that rejects or holds a payment.
  • Return reason (ExternalReturnReason1Code): in a payment return (pacs.004) after the money has moved, and the returned entry on the account statement (camt.053) or notification (camt.054).

In a status report, MS03 explains a status such as RJCT, at transaction level here (the same StsRsnInf block can sit under the group or a payment block):

pain.002.001.10 · a rejected transaction
<OrgnlPmtInfAndSts>
  <OrgnlPmtInfId>PMT-20261028-03</OrgnlPmtInfId>
  <TxInfAndSts>
    <OrgnlEndToEndId>INV-2026-0042</OrgnlEndToEndId>
    <TxSts>RJCT</TxSts>
    <StsRsnInf>
      <Rsn>
        <Cd>MS03</Cd>
      </Rsn>
      <AddtlInf>Free text from the bank, if any</AddtlInf>
    </StsRsnInf>
  </TxInfAndSts>
</OrgnlPmtInfAndSts>

What to do about MS03

  • If you sent the payment or the collection: Ask your bank to investigate with the other bank. Sending the same payment again usually fails the same way.

Your bank’s implementation guide and the scheme’s rulebook (for SEPA, the EPC rulebooks) say exactly when it may use MS03; banks do not all apply a code the same way.

Look up MS03 from a script or an AI agent

Scripts and AI agents get this code’s name, definition, where it sits and the address of this page from GET /api/v1/explain, keyless, or from the explain_code tool of the MCP server (API and MCP docs; add it to Claude, Cursor or VS Code).

REST · curl
curl -s 'https://iso20022-navigator.com/api/v1/explain?code=MS03&kind=status_reason'