IBAN & VAT Validator
Check whether an international IBAN or an Italian VAT number (Partita IVA) is well-formed, right in your browser. No data sent to any server.
Enter a value to validate it.
What the validator does
This tool checks the formal correctness of two widely-used identifiers: the IBAN (International Bank Account Number) and the Italian VAT number (Partita IVA). Pick a mode, paste the value, and get the validation result plus a breakdown instantly. All computation happens in your browser: no data is sent or stored.
For the IBAN it applies the standard ISO 13616 algorithm: it checks the format, that the length matches the one expected for the country (for SEPA and major countries) and, above all, the check digits via the mod-97 computation. It also shows the country code, the check digits, the BBAN and the IBAN formatted in groups of four.
For the Italian VAT number it checks the structure (11 digits) and the final check digit, computed with the official algorithm. Important: validation only confirms the code is well-formed — not that the bank account or company actually exists or is active. For that you need official services (e.g. VIES for European VAT numbers).
The most common use case is checking an IBAN before a wire transfer, to catch a transcription error (a swapped digit, a stray space) before sending the payment, or checking a supplier's Italian VAT number on an invoice to catch typos before recording it in your books. It's also useful during development, to quickly generate valid and invalid test cases when building an IBAN or VAT number input form in an application.
The most common IBAN transcription mistakes are swapping two adjacent digits and substituting a letter for a visually similar digit (like O for 0): the mod-97 checksum catches nearly all of these. In detail, the computation moves the first four characters to the end of the string, converts each letter to its corresponding number (A=10, B=11, … Z=35), and checks that the resulting number, divided by 97, leaves a remainder of exactly 1 — any other remainder means an invalid IBAN. One thing not to confuse: the IBAN identifies an account, while the BIC/SWIFT code identifies a bank — they're two distinct codes, and a tool like this needs the former, not the latter. For the Italian VAT number, keep in mind that self-employed professionals under the flat-rate ("forfettario") scheme often hold a VAT number but may invoice without charging VAT: the number's formal validity doesn't depend on which tax regime applies, which this tool does not check.
Frequently asked questions
- Does it verify the account or company actually exists?
- No. The tool only checks formal correctness (structure and check digit). It does not verify that the bank account is active or that the VAT number belongs to a real company — for that you need official services (e.g. VIES for EU VAT numbers).
- Which IBAN countries are supported?
- The mod-97 checksum works for any IBAN. Length is verified for SEPA and major countries; for countries not in the list the check digits are still validated.
- Is the data sent to a server?
- No. All validation happens in your browser. No IBAN or VAT number is transmitted or stored.
- What does BBAN mean?
- The BBAN (Basic Bank Account Number) is the part of the IBAN that identifies the bank and account nationally — everything after the country code and the two check digits.