IBAN Validator & Checker

What Is an IBAN? How Many Digits in an IBAN?

IBAN (International Bank Account Number) is a numbering system used to express account details in a standard format for international money transfers. This free IBAN decoder and IBAN lookup tool reads any number you enter and breaks it into its parts. Developed in 1997 by the European Committee for Banking Standards (ECBS), the standard was made international with ISO 13616. A common question is how many digits in an IBAN — the answer depends on the country, as the table further down shows.

IBAN length varies by country. A Turkish IBAN, for example, has 26 characters, made up of these components:

• TR — Turkey country code (2 characters)
• Check digits — 2 digits computed with the MOD97 algorithm
• Bank code — 4 digits identifying the bank
• Reserve digit — 1 digit, always 0 in Turkey
• Account number — 17 digits

IBAN Digit Count — Length by Country Table

The international IBAN length differs by country, so the IBAN digit count is not fixed. The question how many characters is an IBAN is answered differently for each country. The table below shows the IBAN lengths of commonly used countries:

How to Tell Which Bank an IBAN Belongs To

The question of which bank an IBAN belongs to is answered, for Turkish IBANs, by looking at characters 5 to 8 (the 4-digit bank code). This tool performs the bank lookup automatically for TR IBANs; knowing the bank codes is both practical and educational.

• 0001 — Ziraat Bankasi
• 0006 — Is Bankasi
• 0010 — Halkbank
• 0012 — VakifBank
• 0046 — Akbank
• 0062 — Garanti BBVA
• 0067 — Yapi Kredi (YKB)
• 0088 — QNB Finansbank
• 0099 — ING Bank
• 0139 — Kuveyt Turk

This tool includes the codes of all banks operating in Turkey. When you enter a number, the IBAN bank lookup resolves the bank name automatically.

IBAN Validation — How Does the MOD97 Algorithm Work?

As an IBAN checker, this tool runs the MOD97-10 algorithm defined in the ISO 7064 standard to decode IBAN details and verify them. The algorithm mathematically tests the correctness of the check digits. The IBAN check process has these steps:

1. The first 4 characters of the IBAN (country code + 2 check digits) are moved to the end.
2. Letters are converted to numbers: A=10, B=11, ... Z=35.
3. The resulting large number is divided by 97.
4. If the remainder is 1 the IBAN is valid; any other value means it is invalid.

Thanks to this algorithm, the vast majority (over 99%) of typos can be detected. However, MOD97 validation only checks the correctness of the format; to verify that the account actually exists, you must contact the bank.

How to Find the Account Number from an IBAN

To find the account number from an IBAN is quite direct in the Turkish IBAN structure, which is as follows:

• Characters 1-2 (TR): Country code
• Characters 3-4: Check digits (MOD97 validation)
• Characters 5-8: 4-digit bank code
• Character 9: Reserve digit (always 0 in Turkey)
• Characters 10-26: 17-digit account number

So the 17 digits from the 10th character to the end are the account number directly. You can do this in a single step with this tool.

Where Is the IBAN Branch Code?

Regarding the IBAN branch code: in the Turkish IBAN structure, the 9th character that comes right after the bank code (characters 5-8) is the reserve digit, and in Turkey it is always left as 0 (zero) by banks. The real branch information may be embedded in the first few digits of the account number, according to each bank's internal account-number system.

For this reason, to find the branch from an IBAN directly may not always be possible; to learn the branch for certain, consult the relevant bank. This tool shows the branch/reserve code, but reminds you that it may not contain the real branch number according to the bank's own system.

Use Cases for an IBAN

An account number in this format is required in the following situations:

• International money transfer: The number is needed alongside the SWIFT/BIC code.
• Salary setup: Employers register employees in the system with one.
• Standing payment orders: Bills, rent and subscription payments are defined this way.
• Domestic transfers: It is the standard for bank transfers.
• Government payments: Tax refunds and social benefit payments are made to it.

Things to Watch When Transferring Money

Besides checking and validation, some important points deserve attention when transferring money:

• Always get the number from the recipient in writing. Account numbers communicated verbally carry a high risk of typos. Prefer numbers shared via phone or email.
• MOD97 validity does not guarantee the account exists. Even if the format is correct, the account may be closed, frozen or never opened. For high-value transfers, confirm with the bank branch.
• International transfers also need a SWIFT/BIC code. The IBAN alone is sufficient only for transfers within the European SEPA area. Cross-border transfers may also require a SWIFT code.
• Beware of change requests. In social-engineering attacks, fraudsters may send a fake number claiming "the bank account changed". Confirm directly by phone or in person whether the account of the person or organization you are paying has changed.
• Know your transfer types. Transfers to customers of the same bank are instant. Transfers to different banks happen during business hours; transfers sent at night or on weekends post on the next business day.

IBAN Security and Common Mistakes

IBAN numbers do not contain enough information to access a bank account; they are used only to receive money transfers. Still, this information in the wrong hands can lead to various risks. Building a habit of IBAN checking reduces these risks.

• An IBAN can belong to a fake account: Fraudsters can generate realistic-looking IBANs. This tool runs MOD97 validation; but only the bank can confirm whether the account belongs to a real institution.
• A single-digit difference makes a big difference: In an IBAN, changing one digit can send money to a completely different account. Compare the IBAN before every transfer.
• An incorrectly entered IBAN can pass MOD97: Although unlikely, in theory a wrong IBAN can pass the MOD97 test. So confirm with the recipient before transferring.
• E-commerce fraud: In a sale, the other party may send an IBAN. Sending money to an IBAN without verification can mean losing the money before the product is delivered. IBAN tools show the bank name; check which bank it belongs to before paying.

How to Use This IBAN Validator

Paste the IBAN (with or without spaces) into the input field and click the "Parse & Validate" button. The tool validates whether the IBAN is correct with the MOD97 algorithm, parses the bank code to show the bank name (for TR IBANs), and breaks down the check digits and account number. Everything happens in your browser; your IBAN is never sent to a server. In the FAQ section you can find more information on IBAN length, which bank an IBAN belongs to, and IBAN validation.