How long is a Polish IBAN?

Exactly 28 characters, one of the longest in Europe. The structure is PL, two check digits, an 8-digit NRB routing block, and a 16-digit account number. Anything shorter or longer is invalid.

What is the NRB in a Polish IBAN?

The NRB (Numer Rachunku Bankowego) is the 26-digit Polish domestic account number. The Polish IBAN is simply PL plus the full NRB, so the 8-digit routing block here is the bank, branch, and NRB control portion.

How does the MOD-97 check work?

The first four characters are moved to the end, each letter is replaced by a number (A=10 to Z=35), and the result is divided by 97. The remainder must equal 1 for the IBAN to be structurally valid.

Does a valid result mean the account exists?

No. MOD-97 catches typos and transposed digits but cannot confirm the account is real or open. Only the bank can confirm that.

Is my IBAN sent anywhere?

No. All validation runs locally in JavaScript. Nothing is uploaded, logged, or stored, and the tool works offline once loaded.

Poland IBAN Validator

Polish IBANs are 28 characters long and are built directly from the domestic NRB (Numer Rachunku Bankowego). Because the NRB itself is 26 digits, a single dropped digit is easy to miss by eye. This validator confirms the full structure and checksum instantly, entirely in your browser.

How it works

A Polish IBAN always begins with PL, followed by two check digits, an eight-digit NRB routing block (bank, branch, and the internal NRB control digit), and a sixteen-digit account number:

PL  kk  bbbbbbbb  aaaaaaaaaaaaaaaa
^   ^   ^         account number (16 digits)
|   |   NRB routing (8 digits)
|   check digits (2)
country code

The validator runs three checks: the length must be exactly 28; the 24-digit BBAN must be all digits; and the ISO 7064 MOD-97-10 checksum must pass. For the checksum the first four characters (PLkk) are moved to the end, every letter is replaced by its numeric code, and the resulting long integer must leave a remainder of 1 when divided by 97. The computation is folded digit-by-digit to stay within JavaScript’s safe integer range.

Worked example

Take PL61 1090 1014 0000 0712 1981 2874: country code PL, check digits 61, routing 10901014, account 0000071219812874. Rearranging the IBAN and dividing by 97 leaves remainder 1, so the checksum passes.

Tips

When converting from a domestic NRB, write the two leading control digits as the IBAN check digits right after PL and keep every leading zero in the account block. Dropping a zero shortens the IBAN and fails the length check immediately. All figures are processed locally and never uploaded.