What does AC03 mean in ISO 20022?

AC03 is Invalid Creditor Account Number in the ExternalCancellationReason1Code code set: Wrong account number in Credit Transfer.

What should I do when I get AC03?

Ask the beneficiary to confirm the account number in writing. Fix the data in the payment order and send a new payment with a new reference and a new UETR. A rejected or returned payment cannot be repaired and resent under its old identifiers.

Where does AC03 appear in a message?

For example in camt.056, element Undrlyg/TxInf/CxlRsnInf/Rsn/Cd.

ExternalCancellationReason1Code

AC03 Reason Code: Invalid Creditor Account Number

Written and maintained by ZagTrader. Last reviewed 21 October 2026. How this page is sourced and checked

AC03 means invalid creditor account number in the ISO 20022 cancellation reason code set. The creditor (beneficiary) account is missing or not valid.

Code: AC03
ISO name: InvalidCreditorAccountNumber
Status: Registered
Last updated: 2017-11-01

Official definition

Wrong account number in Credit Transfer.

Definition from the ISO 20022 External Code Sets, 2Q2026 (published 28 Aug 2026).

What it means in practice

In a camt.056 cancellation request (or camt.055 from a customer), a cancellation reason code explains why the sender asks for a payment to be stopped or its funds returned. It sits in Undrlyg/TxInf/CxlRsnInf/Rsn/Cd.

The creditor (beneficiary) account is missing or not valid. Some schemes use AC03 where others use AC01; in SEPA credit transfers it is the usual code for a wrong IBAN on the beneficiary side.

What to do

Ask the beneficiary to confirm the account number in writing.
Fix the data in the payment order and send a new payment with a new reference and a new UETR. A rejected or returned payment cannot be repaired and resent under its old identifiers.

Messages and fields that use ExternalCancellationReason1Code

Message	Element path
camt.056	Undrlyg/TxInf/CxlRsnInf/Rsn/Cd, Undrlyg/OrgnlGrpInfAndCxl/CxlRsnInf/Rsn/Cd
camt.008	CxlRsn/Rsn/Cd
camt.037	Dtl/CxlRsn/Cd
camt.055	Undrlyg/OrgnlGrpInfAndCxl/CxlRsnInf/Rsn/Cd, Undrlyg/OrgnlPmtInfAndCxl/CxlRsnInf/Rsn/Cd, Undrlyg/OrgnlPmtInfAndCxl/TxInf/CxlRsnInf/Rsn/Cd
camt.110	InvstgtnData/AddtlReqData/ReqdDbtAuthstn/CxlRsn/Cd
camt.116	versions 001.01

AC03 in other code sets

AC03 questions

What does AC03 mean in ISO 20022?: AC03 is Invalid Creditor Account Number in the ExternalCancellationReason1Code code set: Wrong account number in Credit Transfer.
What should I do when I get AC03?: Ask the beneficiary to confirm the account number in writing. Fix the data in the payment order and send a new payment with a new reference and a new UETR. A rejected or returned payment cannot be repaired and resent under its old identifiers.
Where does AC03 appear in a message?: For example in camt.056, element Undrlyg/TxInf/CxlRsnInf/Rsn/Cd.

All ExternalCancellationReason1Code codes · ISO 20022 code sets

The ISO 20022 code names and definitions on this page are reproduced from material published at iso20022.org under the ISO 20022 Intellectual Property Rights policy. This is not the official source: the up-to-date ISO 20022 standards and repository material are published only at iso20022.org. Explanations in our own words are by ZagTrader. ZagTrader is not affiliated with or endorsed by ISO or Swift.