Complete IBAN Guide: Formats & Validation
What is IBAN (International Bank Account Number)?
The International Bank Account Number (IBAN) is a globally recognized standard for identifying bank accounts across national borders. Introduced by the European Committee for Banking Standards (ECBS) in 1997, the IBAN system was designed to facilitate international money transfers, reduce errors, and improve the speed and security of cross-border payments.
An IBAN consists of a country code, check digits, bank code, and account number. The length of an IBAN varies by country, typically ranging from 15 to 34 characters. For example, a Turkish IBAN has 26 characters, a German IBAN has 22 characters, and a UK IBAN has 22 characters.
IBAN Structure
Position 1-2: ISO 3166-1 alpha-2 country code (e.g., TR, DE, GB)
Position 3-4: Check digits calculated using mod-97 algorithm
Position 5+: Basic Bank Account Number (BBAN) - country-specific format
Benefits of Using IBAN
- Faster and more secure international money transfers
- Automatic validation of account numbers to prevent errors
- Standardization for cross-border payments within SEPA
- Reduced processing costs and increased automation for banks
- Improved straight-through processing (STP) rates
- Compliance with international banking regulations
Country-Specific IBAN Formats
🇹🇷 Turkey IBAN Format
Length: 26 characters
Structure: TR + 2 check digits + 5 bank code + 1 reserve digit + 16 account number
Example: TR33 0006 2000 0000 0000 0001 23
Bank Code: 5 digits assigned by Central Bank of Turkey
Account Number: 16 digits (including branch and account identifier)
🇩🇪 Germany IBAN Format
Length: 22 characters
Structure: DE + 2 check digits + 8 bank code (BLZ) + 10 account number
Example: DE89 3704 0044 0532 0130 00
Bank Code (BLZ): 8 digits identifying the bank
Account Number: 10 digits (padded with leading zeros if necessary)
🇬🇧 United Kingdom IBAN Format
Length: 22 characters
Structure: GB + 2 check digits + 4 bank code + 6 sort code + 8 account number
Example: GB82 WEST 1234 5698 7654 32
Bank Code: 4 letters identifying the bank
Sort Code: 6 digits identifying the branch
Account Number: 8 digits
🇫🇷 France IBAN Format
Length: 27 characters
Structure: FR + 2 check digits + 5 bank code + 5 branch code + 11 account number + 2 key
Example: FR14 2004 1010 0505 0001 3M02 606
Bank Code: 5 digits
Branch Code: 5 digits
Account Number: 11 characters (alphanumeric)
Key: 2 digits (RIB check key)
🇮🇹 Italy IBAN Format
Length: 27 characters
Structure: IT + 2 check digits + 1 CIN + 5 ABI + 5 CAB + 12 account number
Example: IT60 X054 2811 1010 0000 0123 456
CIN: 1 character check digit
ABI: 5 digits (bank identifier)
CAB: 5 digits (branch identifier)
Account Number: 12 characters
🇪🇸 Spain IBAN Format
Length: 24 characters
Structure: ES + 2 check digits + 4 bank code + 4 branch code + 2 control digits + 10 account number
Example: ES91 2100 0418 4502 0005 1332
Bank Code: 4 digits
Branch Code: 4 digits
Control Digits: 2 digits (Spanish check digits)
Account Number: 10 digits
IBAN Validation and Check Digit Calculation
IBAN validation follows the ISO 13616 standard using the mod-97 algorithm. Here's how the check digits are calculated:
- Move the first 4 characters to the end of the string
- Replace each letter with its corresponding number (A=10, B=11, ..., Z=35)
- Calculate mod 97 of the resulting number
- Subtract the result from 98 to get the check digits
- If the result is less than 10, pad with a leading zero
Common Validation Errors
- Incorrect country code (must be valid ISO 3166-1 alpha-2)
- Wrong IBAN length for the specific country
- Invalid check digits (mod-97 validation fails)
- Non-alphanumeric characters in positions that require numbers only
- Bank codes that don't exist in the country's banking system
Why Use Our IBAN Generator?
Our IBAN Generator creates valid, random IBAN numbers for testing, development, and educational purposes. It's particularly useful for:
Software Testing
Generate test IBAN data for payment system testing, form validation, and QA processes without using real bank account numbers.
API Development
Use valid IBAN formats in your applications, APIs, and database seeding for fintech and banking software development.
Education
Teach IBAN formats, international banking standards, and payment processing using realistic but safe test data.
Important: Generated IBANs are for testing and educational purposes only. They are not linked to real bank accounts and must never be used for actual financial transactions.
Frequently Asked Questions
How do I validate a Turkish IBAN?
Turkish IBANs must be 26 characters long, start with "TR", followed by 2 check digits and 22 additional digits. Use our IBAN validator to check if a Turkish IBAN is correctly formatted and has valid check digits.
What's the difference between German and UK IBAN formats?
Both German and UK IBANs are 22 characters long, but their internal structure differs. German IBANs use an 8-digit bank code (BLZ) followed by a 10-digit account number, while UK IBANs use a 4-letter bank code, 6-digit sort code, and 8-digit account number.
Can I generate IBANs for SEPA countries?
Yes, our generator supports all SEPA (Single Euro Payments Area) countries including Germany, France, Italy, Spain, Netherlands, Austria, Belgium, and many more. Each follows their country-specific IBAN format.
How accurate are the generated bank codes?
Our generator uses real bank codes and follows the exact format specifications for each country. However, the generated IBANs are random combinations and don't correspond to actual bank accounts.
Is IBAN mandatory for international transfers?
IBAN is mandatory for transfers within SEPA countries and required by many banks worldwide for international transfers. Over 70 countries now use IBAN for cross-border payments to ensure accuracy and efficiency.
What should I do if IBAN validation fails?
If IBAN validation fails, check the country code, IBAN length, and ensure all characters are correct. Common issues include wrong country codes, incorrect length, or typos in the number sequence.