Poland uses a 28-character IBAN whose BBAN is 24 digits, pattern ^[0-9]{24}$. Its defining trait is that the domestic and international formats are the same number: the 26-digit NRB is simply the IBAN minus the letters PL.
Structure
The registry example PL61 1090 1014 0000 0712 1981 2874 (a SWIFT registry test value, not a live account) parses as:
PL61- country code and check digits; the digits 61 also serve as the NRB’s leading check pair domestically10901014- the 8-digit rozliczeniowy (routing) number: bank code, branch digits, and a trailing national control digit0000071219812874- the 16-digit account number
One number, two names
Because the NRB standard was designed after the IBAN existed, Poland aligned the two completely. A Polish payslip or invoice typically shows 26 digits grouped 2-8-16; international documents show the same digits behind PL. This eliminates the conversion errors seen in countries where the domestic format predates the IBAN and requires padding or reordering.
The 8-digit routing number carries its own weighted control digit in the final position, so Polish IBANs have layered integrity: the routing field self-checks, and the whole string is covered by ISO 7064 MOD-97. The 16-digit account portion is left to each bank’s internal scheme.
SEPA and currency notes
Poland is an EU and SEPA member while retaining the złoty. PL IBANs are used both for domestic PLN payments over the Elixir system and for euro SEPA credit transfers and direct debits; the same account number serves both rails, though the account itself may be denominated in either currency, which is worth confirming with the beneficiary before sending euros.
A structurally valid PL IBAN, even with the routing check digit passing, remains only a plausible number. It does not establish that the account is open or who controls it. EU Verification of Payee name matching is the control that catches a well-formed IBAN pointing to the wrong recipient. For test data, use the generator on this page rather than constructing digits by hand.