Poland uses one of the longest IBANs a European integration will encounter: 28 characters, entirely numeric after the country code. A Polish test IBAN consists of PL, two mod-97 check digits, an 8-digit routing number identifying the bank and branch, and a 16-digit account number. Strip the PL prefix and you have the 26-digit NRB, the domestic format Polish users type into local banking forms, which is a useful fact when your tests need to cover both representations of the same account.
Why length itself is a test case
At 28 characters, PL IBANs are excellent for flushing out UI bugs: input fields with maxlength set for shorter countries, database columns sized too tightly, display components that truncate, and copy-paste handling of the grouped “PL61 1090 1014 …” spacing. If your product supports multiple SEPA countries, include a Polish value in your fixture set specifically to exercise the long end of the range.
There is also a structural subtlety: the 8-digit routing segment embeds its own check digit, computed with a weighted modulo algorithm over the preceding digits. Concatenating random digits and then fixing the outer mod-97 check produces an IBAN that generic libraries accept but that a Polish clearing-aware validator rejects. The generator on this page builds the routing part consistently, so the output is coherent at both layers.
Sandbox and CI usage
Payment sandbox onboarding for the Polish market, unit tests for pesel-adjacent KYC forms that also collect bank details, and load scripts creating synthetic PLN payout recipients all need well-formed PL IBANs. Generate them here one at a time; the tool runs entirely in your browser, transmits nothing, and labels every output TEST.
The usual caveat, stated plainly
A structurally valid IBAN is a string that satisfies rules, not an account that holds money. None of these values exist at any Polish bank. Use them for testing, never for real transfers or to misrepresent payment details; EU Verification of Payee checks now match names to IBANs before euro payments execute.