What is an Italian IBAN and how long is it?

An Italian IBAN (Codice IBAN) is always exactly 27 characters: the two-letter country code IT, two check digits, and a 23-character BBAN (Basic Bank Account Number) made up of a single CIN letter, a 5-digit ABI bank code, a 5-digit CAB branch code and a 12-character account number.

What is the MOD-97 checksum and why does it matter?

The ISO 7064 MOD-97-10 algorithm converts the rearranged IBAN to a long number and divides by 97. If the remainder is exactly 1 the structure is correct. Any single transposition or mis-typed digit changes the remainder, so most keying errors are caught before a payment is sent.

What is the CIN character in an Italian IBAN?

The CIN (Codice di Controllo Interno) is a single uppercase letter at position 5 of the IBAN (after the two-letter country code and two check digits). It is computed from the ABI, CAB and account number using the Luhn-style algorithm defined by the Banca d Italia, and provides an extra layer of integrity checking on top of the overall IBAN MOD-97 checksum.

What are the ABI and CAB codes?

The ABI (Associazione Bancaria Italiana) code is a 5-digit number that identifies the bank, assigned by the Italian Banking Association. The CAB (Codice di Avviamento Bancario) is a second 5-digit number that identifies the specific branch. Together they form the first 10 digits of the BBAN portion and pinpoint the exact branch at which the account is held.

Can this tool confirm that the account actually exists?

No. A "valid" result means the IBAN is structurally correct and passes all format rules. Only your bank or the recipient bank can confirm that an account with this number is open and can receive funds. Always double-check account details directly with the account holder before sending money.

Is my banking data safe when I use this tool?

Completely. The entire validation runs inside your browser using JavaScript. No IBAN, no account number and no personal data of any kind is ever sent to a server. You can even use this tool offline once the page has loaded.

Italian IBAN Validator

An Italian IBAN validator that checks every structural layer of the number in real time — the ISO 7064 MOD-97-10 checksum, the CIN control character, the ABI bank code, the CAB branch code and the 12-character account number format. It is aimed at anyone who needs to verify a codice IBAN before making a bank transfer, integrating it into a form, or sharing it with a payroll system.

How it works

Italy adopted the IBAN standard (ISO 13616) for all domestic and international bank transfers. Every Italian IBAN is exactly 27 characters and follows a fixed layout:

Position	Length	Field	Content
1-2	2	Country code	Always `IT`
3-4	2	Check digits	Computed by MOD-97
5	1	CIN	Internal control letter, A-Z
6-10	5	ABI	Bank identifier, all digits
11-15	5	CAB	Branch identifier, all digits
16-27	12	Account	Alphanumeric account number

The validator runs three independent checks.

Check 1 — ISO 7064 MOD-97-10 (overall IBAN checksum). The first four characters are moved to the end, then every letter is expanded to its two-digit numeric equivalent (A = 10, B = 11 … Z = 35). The resulting number is divided by 97 using progressive remainder arithmetic (so no overflow occurs even for long IBANs). The IBAN is structurally valid if and only if the remainder equals exactly 1.

Check 2 — Length and country code. Italian IBANs are always 27 characters. Any deviation — a miscount when copying, a truncated paste, or an IBAN from another country — is flagged immediately with the actual versus expected length.

Check 3 — BBAN sub-field formats. Even after passing MOD-97, the tool inspects each field individually: the CIN position must be a single letter A-Z, the ABI and CAB fields must each be exactly 5 digits, and the account number must be exactly 12 alphanumeric characters. This catches malformed IBANs that happen to pass the checksum by coincidence.

Worked example

Suppose you receive the IBAN IT60 X054 2811 1010 0000 0123 456 (a well-known test value used in Italian banking documentation). After stripping spaces the input is IT60X054281110100000123456 — 27 characters.

Rearrange and expand: move IT60 to the end, expand all letters. The CIN X becomes 33, I becomes 18, T becomes 29. Building the numeric string and folding mod 97 gives a remainder of 1 — checksum passes.
BBAN breakdown:
- CIN = X (a valid uppercase letter)
- ABI = 05428 (5 digits, valid)
- CAB = 11101 (5 digits, valid)
- Account = 000000123456 (12 alphanumeric, valid)
Result: every check passes — the IBAN is structurally valid.

Now change the last digit to 7 (IT60X054281110100000123457). The MOD-97 remainder is no longer 1, so the checksum fails immediately — you see “Invalid — MOD-97 checksum failed” in red. This is exactly how IBANs protect against single-digit transcription errors.

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