French IBAN format (FR) — length, structure, example

France encodes its long-standing RIB (Relevé d’Identité Bancaire) directly into a 27-character IBAN. The BBAN pattern is ^[0-9]{10}[A-Z0-9]{11}[0-9]{2}$: ten digits, eleven alphanumeric characters, then two final digits.

From RIB to IBAN

The official registry example is FR14 2004 1010 0505 0001 3M02 606 - a SWIFT registry test value, not a real account. Reading it left to right:

• FR14 - country code and IBAN check digits
• 20041 - code banque, the 5-digit bank identifier
• 01005 - code guichet, the 5-digit branch (counter) code
• 0500013M026 - the 11-character account number; note the letter M, which is allowed here
• 06 - the clé RIB, France’s own 2-digit check key

Every element after the check digits is a field French customers have used for decades on their RIB slips. The IBAN adds nothing new; it simply wraps the RIB in the international envelope.

The dual-check system

France belongs to the small group of countries (with Belgium, Spain, Portugal, Hungary and others) whose BBAN carries its own domestic check mechanism. The clé RIB is derived by a modulo-97 computation across bank code, branch code and account number, with letters mapped to digits first. A validator that knows the French rules can therefore catch errors twice: a typo usually breaks the IBAN checksum, and if by rare coincidence it does not, it will almost certainly break the clé RIB.

SEPA and practical notes

France is a SEPA member, so FR IBANs are first-class citizens for euro credit transfers and direct debits. French overseas territories are a frequent source of confusion: departments such as Guadeloupe, Martinique and Réunion use FR IBANs, while some collectivities have their own country codes that share the French BBAN layout. As always, a structurally valid FR IBAN proves formatting only. It does not prove the account exists or that it belongs to your intended payee; EU banks perform Verification of Payee name matching to close that gap before releasing a transfer.