IBAN validator
Checks an IBAN's ISO 13616 mod-97 checksum and its country's length. A pass means the number is well formed, not that the account exists.
Input
IBAN check
—Paste an IBAN to verify its mod-97 check digits.
- Algorithm
- mod-97
- Standard
- ISO 13616
Related tools
Guides
This IBAN validator checks whether an International Bank Account Number is well formed. It strips spaces, uppercases the input, and checks that it's 15 to 34 characters of two letters, two digits, then letters and digits. Next it checks that the country code is one of the 16 it knows and that the length matches that country. Last comes the ISO 13616 mod-97 checksum. The IBAN you type is checked in your browser and isn't sent anywhere.
How to validate an IBAN
- Paste or type the IBAN. Spaces and lowercase letters are fine.
- Or try a built-in example: a valid German IBAN, a valid UK one, or one with broken check digits.
- A valid IBAN shows the country, the number grouped in fours, its length and its check digits.
- An invalid one shows the first problem found, such as the wrong length for its country or a failed checksum.
What a mod-97 pass does and doesn't prove
A pass means the check digits agree with the rest of the number and the length fits the country. That catches most typos, including a single wrong character or two swapped neighbors. It doesn't check country-specific patterns inside the account part, such as the four letters that start a UK bank code. And it can't tell you whether the bank exists, whether the account is open, or whether it can receive money. Only the bank, or a service connected to bank data, can confirm that.
Common reasons an IBAN fails
- Wrong length for the country. Germany and the UK use 22 characters, France 27.
- Checksum failed: one character is wrong or two have been swapped.
- A country this tool doesn't know. It covers AD, AT, BE, CH, DE, ES, FR, GB, GR, IE, IT, LU, NL, NO, PT and SE, so a correct IBAN from Poland or Denmark is rejected too.
- Characters other than letters and digits, or a start that isn't two letters followed by two digits.
Frequently asked questions
Does a valid IBAN mean the bank account exists?
No. It means the format and check digits are right. Whether the account is open and can receive money takes a check with the bank.
How does IBAN mod-97 validation work?
Move the first four characters to the end, replace each letter with two digits (A = 10 through Z = 35), and read the result as one big number. If that number mod 97 equals 1, the check digits are correct.
Does this validator store the IBANs I enter?
No. The check runs in your browser. Your IBAN isn't sent to a server or saved.
Which countries does the IBAN validator support?
16 so far: Andorra, Austria, Belgium, Switzerland, Germany, Spain, France, the UK, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal and Sweden. IBANs from any other country are rejected even when they're correct, so for those a failure means unknown, not wrong.
Built and maintained by Bipul Kumar. Found a wrong number or a broken result? Tell me and I'll fix it.