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SEPA AC01

Incorrect account number

Category: Account R-type: Reject / Return

SCT

Applies

SCT Inst

Applies

SDD Core

Applies

SDD B2B

Applies

Retryable

Yes, after correction

Generated by

Debtor bank (SDD collections) or the clearing infrastructure / beneficiary bank (SCT and SCT Inst credit transfers) — whichever party validates the IBAN.

ISO 20022 definition

Format of the account number specified is not correct.

Typical cause

IBAN format is invalid, the check digit fails, or the account does not exist. Usually a mandate-capture or payment-initiation data-entry error.

What to do about it

Validate the IBAN with an IBAN check-digit tool and contact the customer for the correct account number before resubmitting.

Rulebook note

Same code and meaning across all four rulebooks — the only universal account-number-format code in this set.

Confidence: high. Sourced from PaymentBrief's SEPA R-transaction reference article, cross-verified against ISO 20022 external code sets and EPC guidance documents. Reason-code applicability and timing windows vary by rulebook version and bank handling — verify against your bank or PSP before acting.

Full reference

SEPA Return and Reject Codes: The R-Transaction Reference

Related codes

AC03

Wrong IBAN (creditor)

AC04

Closed account number

AC06

Blocked account