An IBAN decoder reveals the structure hidden inside an International Bank Account Number. Every IBAN starts with a 2-letter country code and 2 check digits, then contains a country-specific bank account identifier. This decoder parses each section and validates the check digits using mod-97 arithmetic per ISO 13616.
Enter IBAN
Spaces are auto-formatted every 4 characters. Check digits are verified with mod-97.
IBAN Structure
How to Use the IBAN Decoder
International Bank Account Numbers are used across Europe and the Middle East for cross-border payments. While an IBAN looks like a random string of letters and digits, every character has a specific meaning. This free IBAN decoder reveals the structure and validates the check digits instantly.
Step 1: Paste or Type the IBAN
Enter the IBAN in the input field above. You can paste it with or without spaces — the tool auto-formats it with a space every 4 characters. The IBAN is automatically converted to uppercase. IBANs range from 15 characters (Norway) to 32 characters (Saint Lucia) depending on country.
Step 2: Read the Color-Coded Structure
The IBAN decoder displays each section in a distinct color. The blue segment is the 2-letter country code (ISO 3166-1 alpha-2). The amber segment is the 2-digit check number. The green segment is the bank code. The teal segment is the branch sort code (where applicable). The purple segment is the account number. Together these form the BBAN — the Basic Bank Account Number.
Step 3: Verify the Check Digits
The IBAN check digits (positions 3-4) are validated using mod-97 arithmetic per the ISO 13616 standard. The tool moves the first 4 characters to the end, converts all letters to two-digit numbers (A=10 through Z=35), and divides the resulting number by 97. A valid IBAN always produces a remainder of 1. The decoder shows whether this check passes or fails.
Step 4: Extract Banking Details
Each country defines exactly how many characters belong to the bank code, branch code, and account number within the BBAN. A UK IBAN (22 chars) has 4 bank code chars and 6 branch/sort code chars. A German IBAN (22 chars) has 8 bank code chars (Bankleitzahl). The decoder applies country-specific format rules to extract each component accurately.
When to Use an IBAN Decoder
Use the IBAN decoder when setting up international wire transfers to verify the recipient's bank details, when troubleshooting rejected payments, when your accounting software requires the bank code and branch code as separate fields, or simply to understand what an IBAN you've received actually represents.
FAQ
What does an IBAN decoder do?
An IBAN decoder breaks down an International Bank Account Number into its component parts: country code, check digits, bank code, branch code, and account number. It also validates the check digits using mod-97 arithmetic to confirm the IBAN is structurally correct.
Is this IBAN decoder free?
Yes, this IBAN decoder is completely free. Paste any IBAN and instantly see the full structural breakdown including bank code and country identification — no account or signup required.
Is my banking data safe?
Yes, all IBAN decoding happens in your browser using JavaScript. Your IBAN data is never sent to any server, stored, or logged. The tool works entirely client-side for complete privacy.
What is the BBAN in an IBAN?
BBAN stands for Basic Bank Account Number — it's the country-specific portion of the IBAN that follows the 2-letter country code and 2-digit check digits. The BBAN contains the bank code, branch code (if applicable), and account number in the format used by that country's banking system.
How does IBAN check digit validation work?
The check digit is validated using mod-97 arithmetic per ISO 13616. The first 4 characters are moved to the end of the IBAN, all letters are converted to numbers (A=10, B=11...Z=35), and the entire string is divided by 97. A valid IBAN produces a remainder of exactly 1.
What countries use IBAN?
Over 80 countries use the IBAN standard, primarily in Europe, the Middle East, and some Caribbean nations. The UK (22 chars), Germany (22), France (27), Italy (27), and Spain (24) are among the largest users. The US and Canada do not use the IBAN system.
What is the difference between IBAN decoder and IBAN validator?
An IBAN validator only checks whether an IBAN is structurally correct. An IBAN decoder goes further — it parses and reveals each component: country code, bank identifier, branch code, and account number based on that country's specific IBAN format.