IBAN / SIRET / VAT Validator client-side ?
How to use IBAN / SIRET / VAT ValidatorThis tool checks the control keys of three common identifiers: the IBAN (international mod-97 key), the French SIREN/SIRET (Luhn checksum) and the French intra-EU VAT number (key derived from the SIREN). It confirms that a number is well-formed and that its key is correct — useful before saving it into invoicing software, a form or a database.
This is a mathematical validation, not an existence check: an IBAN or SIRET can have a correct key without matching a real account or company. To verify existence, use the official registries (VIES for VAT, INSEE/Sirene for companies). Everything is computed locally, with no network call.
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This tool checks the control keys of three common identifiers: the IBAN (international mod-97 key), the French SIREN/SIRET (Luhn checksum) and the French intra-EU VAT number (key derived from the SIREN). It confirms that a number is well-formed and that its key is correct — useful before saving it into invoicing software, a form or a database. This is a mathematical validation, not an existence check: an IBAN or SIRET can have a correct key without matching a real account or company. To verify existence, use the official registries (VIES for VAT, INSEE/Sirene for companies). Everything is computed locally, with no network call.
Check an IBAN, a French SIRET/SIREN or VAT number.
How to use IBAN / SIRET / VAT Validator
This tool checks the control keys of three common identifiers: the IBAN (international mod-97 key), the French SIREN/SIRET (Luhn checksum) and the French intra-EU VAT number (key derived from the SIREN). It confirms that a number is well-formed and that its key is correct — useful before saving it into invoicing software, a form or a database. This is a mathematical validation, not an existence check: an IBAN or SIRET can have a correct key without matching a real account or company. To verify existence, use the official registries (VIES for VAT, INSEE/Sirene for companies). Everything is computed locally, with no network call.
Frequently asked questions
What exactly does it check?
The control key and format: mod-97 for IBAN, Luhn for SIREN/SIRET, the French VAT key. It does not check the real existence of the account or company.
What's the difference between SIREN and SIRET?
SIREN identifies the company (9 digits). SIRET identifies a site (14 digits = SIREN + 5). Both validate via the Luhn checksum.
Are my numbers transmitted?
No. All checking happens in your browser; no network call is made.