Monaco IBAN validator
How the IBAN format works
- Format
- MC + 2 check digits + 5-digit bank code + 5-digit branch code + 11-char account number + 2-digit RIB key (27 chars)
- Example
- MC5811222000010123456789030
Things to watch for
- 27 characters total
- Uses the same BBAN structure as France
^MC[0-9]{2}[0-9]{5}[0-9]{5}[0-9A-Z]{11}[0-9]{2}$A Monaco IBAN is 27 characters: “MC”, two check digits, a 5-digit bank code, a 5-digit branch code, an 11-character account number that can mix digits and letters, and a 2-digit clé RIB — a block-for-block match with France’s IBAN structure. That’s not a coincidence: Monaco’s banks operate under a monetary agreement with France going back decades, and adopted the same domestic account-numbering scheme long before IBAN existed, clé RIB included. Anyone paying a Monaco-based bank, invoicing a client in the principality, or converting an older Monegasque account number to IBAN for a SEPA transfer needs all 27 characters in the right segment — and shouldn’t assume the shared format means the account itself is French.
How this validator works
This tool checks the “MC” prefix, confirms the bank-code and branch-code blocks are 5 digits each, the account-number block is 11 alphanumeric characters, and the clé RIB block is 2 digits, then runs the real mod-97 checksum (ISO 7064) used to generate a valid Monaco IBAN — entirely in your browser, nothing sent to a server, no signup required.
What a pass doesn’t tell you
A pass confirms the 27 characters are correctly formed and internally consistent — not that the account is open, active, or belongs to whoever you expect. This tool doesn’t resolve the bank code to an institution name and never contacts any bank in Monaco or France. If a Monaco IBAN fails, check first whether a letter in the account-number segment got mistaken for a similar-looking digit during copying — the same slip that trips up French IBANs, given the identical block shape.
Scope: Monaco IBAN structure and mod-97 checksum validation only — not payment processing, bank-name lookup, or confirming an account is active, none of which a client-side check can establish. Use this validator to catch a typo before a transfer fails; use your bank to confirm the account itself.
Content last reviewed 2026-07-07.
IBAN FAQ
Why does a Monaco IBAN use the exact same layout as a French one?
Monaco's banking system operates under a long-standing monetary agreement with France, and its domestic account-numbering format was built on the French model — same 5-digit bank code, 5-digit branch code, 11-character account number, and 2-digit clé RIB, all 27 characters long. The IBAN simply carries that shared structure forward.
Does a Monaco IBAN starting with 'MC' mean the account is held in France?
No. The two-letter prefix identifies Monaco as the account's country, not France — Monegasque banks are distinct institutions operating under Monaco's own banking supervision, even though the account-number format they use is identical in shape to France's.
Can the account-number block in a Monaco IBAN contain letters, or is it always digits?
It can contain uppercase letters as well as digits, just like the equivalent French block — this tool accepts either. Confirming what a specific account number actually contains, however, requires checking against your bank statement or banking app, not this validator.