What Is an IBAN Number?

IBAN stands for International Bank Account Number. It is a standardized format that identifies bank accounts across borders, used in more than 80 countries ^[8]. SWIFT maintains the IBAN system under ISO 13616 and publishes a registry of every country's IBAN format ^[8].

Every IBAN starts with a two-letter country code, followed by two check digits, then a country-specific sequence called the BBAN (Basic Bank Account Number). The check digits let any bank or payment system verify the number before processing a transfer. In the European Union, IBAN became mandatory for euro credit transfers and direct debits under SEPA Regulation EU 260/2012, which took full effect in February 2014 for eurozone countries ^[7].

If you live in Poland or send money to someone here, you will see Polish IBANs on invoices, in banking apps, and on government forms.

What Does a Polish IBAN Look Like?

A Polish IBAN contains exactly 28 characters ^{[6] [8]}:

PL + 2 check digits + 8-digit bank sort code + 16-digit account number

The country code is always PL. The MOD 97 algorithm, defined in ISO 7064, produces the two check digits ^[8]. The remaining 24 digits form the BBAN: an 8-digit bank sort code (numer rozliczeniowy) and a 16-digit client account number.

Here is a Poland IBAN example:

PL 61 1090 1014 0000 0001 3210 0010

In this example, 61 is the check digit pair, 10901014 is the bank sort code, and 0000000132100010 is the client account number.

Without the PL prefix, a Polish bank account number has 26 digits. Adding PL to the front converts it to the full IBAN format ^[6]. Most Polish banks display both formats in their apps and on statements.

This is the standard Poland bank account number format. Every Polish IBAN follows it, whether the account sits at PKO BP, mBank, ING, or a local credit union.

How to Verify an IBAN Online

This free IBAN checker validates a Polish bank account number in three steps.

Step 1: Length and format. A valid Polish IBAN must be exactly 28 characters starting with PL, or 26 digits without the prefix. Any deviation fails immediately.

Step 2: MOD 97 checksum. The IBAN validator moves the first four characters to the end of the string, converts letters to their numeric equivalents, and divides the resulting integer by 97 ^[8]. If the remainder equals 1, the checksum passes. Any other result means the number contains an error: a mistyped digit, a transposed pair, or a fabricated sequence.

Step 3: Bank sort code lookup. The tool checks the 8-digit bank sort code against the NBP clearing directory ^[3]. Every active bank and credit union in Poland has at least one registered sort code. If the code does not appear in the directory, the account number may be outdated or incorrect.

When validation fails, the IBAN verifier tells you exactly what went wrong: incorrect length, failed checksum, or unrecognized sort code.

You can check IBAN online using the tool above. Paste the number, and results appear instantly. The IBAN checker is free and requires no registration.

Identify Which Bank an IBAN Belongs To

The first eight digits after the check digits identify the bank. NBP assigns this 8-digit bank sort code and records it in the EWIB 2.0 directory ^{[2] [3]}.

The IBAN checker doubles as an IBAN decoder, IBAN identifier, and bank lookup tool. Paste any Polish account number to identify the bank from the IBAN. The tool extracts the sort code, matches it to a bank name, and displays the result. This helps when you receive an account number on an invoice or by email and want to confirm it belongs to the bank the sender claims.

You can also find the bank from an account number you already have on file. The sort code prefix narrows it to a specific institution within seconds.

No tool can check IBAN owner details from the number alone. An IBAN identifies the bank and branch, not the person. To verify account ownership for business or tax purposes, use the Ministry of Finance's biała lista tool (see below).

The sort code itself contains a check digit in its eighth position, calculated using a modulo 10 formula with weights 3, 9, 7, 1 ^{[2] [5]}. The IBAN checker validates this automatically.

The Bank Sort Code in a Polish Account Number

The 8-digit sort code sits at positions 3 through 10 of the 26-digit account number, or positions 5 through 12 of the full IBAN. The NBP regulation on bank numbering defines its structure ^[2]:

• Digits 1 to 3: institution number assigned to the bank
• Digit 4: internal organizational code
• Digits 5 to 7: branch or unit identifier
• Digit 8: check digit calculated with modulo 10 and weights 3, 9, 7, 1

NBP maintains the full directory of active sort codes through the EWIB 2.0 system at ewib.nbp.pl ^[3]. Banks and credit unions receive new sort codes when they open branches or restructure. NBP retires old sort codes when banks merge.

The legal basis for this numbering system is Article 68 of the Polish Banking Law, which delegates sort code and account numbering rules to the President of NBP ^[1].

NRB — The Polish Account Number Standard

Before IBAN became widespread, Poland used its own 26-digit format called NRB (Numer Rachunku Bankowego). Polish Standard PN-F-01102 defines the NRB format, and the NBP regulation references it directly ^[2].

In practice, the NRB and the BBAN portion of a Polish IBAN are the same 26-digit number. The difference is purely presentational: NRB is the domestic format, and IBAN adds the PL prefix plus two check digits for international compatibility ^{[5] [6]}.

Polish banks accept both formats for domestic transfers. SEPA requires the full IBAN format for international transfers ^[7].

IBAN, BIC, and SWIFT Codes

An IBAN identifies a specific bank account. A BIC (Bank Identifier Code), also called a SWIFT code, identifies the bank itself ^[6]. A BIC is 8 or 11 characters long.

When sending money internationally, you typically need both the recipient's IBAN and the bank's BIC/SWIFT code. SEPA dropped the BIC requirement in February 2016 for euro payments, so the IBAN alone is enough within the eurozone ^[7]. For transfers in Polish złoty from outside the EU, or for non-SEPA currencies, you still need the BIC.

You can find your bank's BIC/SWIFT code on their website, in your banking app, or on your account statement.

When You Should Check an IBAN

Verify an IBAN before any first-time transfer. You can verify IBAN numbers from any Polish bank in seconds. This matters most when you received the number by email, SMS, or messaging app, where digits can be mistyped or tampered with.

Paying a Polish invoice: copy the account number from the invoice into the IBAN number checker to confirm the format and bank before entering it in your banking app.

Setting up a new payee: if a landlord, employer, or business partner sends you their account number, run it through the bank account checker to confirm the digits are valid and the bank matches expectations.

Receiving an unexpected payment request: if someone sends you a bank account number you have not seen before, checking it takes a few seconds and can flag obvious problems.

The checker validates format, checksum, and bank sort code. It does not confirm account ownership or check whether the account is active. For that level of verification, you need additional tools or direct confirmation from the bank.

IBAN and the Biała Lista (VAT Whitelist)

If you run a business in Poland, you may need to verify that a supplier's bank account appears on the biała lista (VAT taxpayer whitelist). Since January 2020, businesses cannot deduct payments over 15,000 PLN made to accounts not listed on the biała lista ^[9].

The biała lista is a separate system maintained by the Head of KAS (National Revenue Administration) ^[9]. Our IBAN checker validates technical correctness: format, checksum, and bank sort code. The biała lista verifies tax registration. For VAT whitelist checks, use the official search tool at podatki.gov.pl ^[9].

Frequently Asked Questions

References

1. Banking Law (Prawo bankowe) — Art. 68, Consolidated Text, Dz.U. 2024 poz. 1646 — isap.sejm.gov.pl
2. NBP President's Regulation on Bank and Account Numbering (Zarządzenie nr 7/2017), Consolidated Text, Dz. Urz. NBP 2025 poz. 29 — dzu.nbp.pl
3. EWIB 2.0 — NBP Online Directory of Financial Institutions — ewib.nbp.pl
5. NBP Analytical Report: Bank and Account Numbering — History and Current State (June 2014) — nbp.pl
6. European Consumer Centre Poland — What is IBAN and BIC/SWIFT? — konsument.gov.pl
7. EU Regulation 260/2012 (SEPA Regulation) — eur-lex.europa.eu
8. SWIFT — IBAN Registry (ISO 13616) — swift.com
9. VAT Taxpayer Register (Biała Lista) — Biznes.gov.pl Guide — biznes.gov.pl