How are IBANs built?
Country Code
2-letter ISO code (e.g., DE, FR, GB)
Check Digits
2 digits calculated using the MOD-97-10 algorithm
BBAN
Combination of bank identifier, branch code, and account number
When do you need an IBAN?
You need an IBAN whenever you send or receive money from countries that use the IBAN system. Common scenarios include:
- 01International payments to IBAN countries
- 02SEPA transfers across the EU, EEA, and other SEPA-member states
- 03Business payouts, supplier payments, and salary transfers in Europe
- 04Receiving money from overseas when the sender’s bank requires an IBAN
- 05Marketplace payouts, freelancer payments, and vendor settlements in IBAN-supported countries
What happens if you enter the wrong IBAN?
Entering an incorrect IBAN can disrupt your international payment. Banks may reject the transfer instantly if the checksum fails, or if the checksum is valid but the details are wrong, or the payment may even go to the wrong branch or account. Some banks return the funds automatically, while others may hold it for manual investigation. You may be charged return or investigation fees too.
Common mistakes to look out for
Incorrect IBAN length
Missing or extra characters compared to the country’s fixed IBAN length.
Invalid check digits
The checksum doesn’t match the MOD-97 calculation, making the IBAN invalid.
Wrong country code
Using an incorrect or non-IBAN country code in the first two letters.
Typing mistakes in the BBAN
A wrong digit in the bank or account number, often caused by manual entry.
Frequently asked questions
An IBAN (International Bank Account Number) is a standard format used in many countries for international payments. It includes a country code, check digits, and the customer’s bank and account details. The purpose of an IBAN is to make cross-border payments faster and reduce errors.
Banks in Europe, the UK, and other IBAN-using countries require an IBAN to process international payments. Without it, your transfer may be delayed or rejected. You do not need an IBAN for transfers to the US, Canada, Australia, India, and other non-IBAN countries.
No. IBAN identifies the specific bank account. SWIFT/BIC identifies the bank. Many international transfers require both.
No. An IBAN checker verifies the format, structure, length, and checksum, but it cannot confirm whether the account is active or belongs to the correct person. It helps detect formatting mistakes before the payment is sent.
IBAN length varies by country, typically between 15 and 34 characters. Each country has a fixed, predefined length. Xflow’s IBAN checker automatically verifies whether the IBAN matches that standard.
No. The US uses routing numbers and account numbers instead of IBANs. IBANs are mainly used in Europe, the UK, the Middle East, and certain regions in Asia and Africa.
If your bank is in an IBAN-using country, you can find your IBAN in the following ways: 1. In your online banking portal 2. On your bank statements 3. By contacting your bank directly.
If you enter an incorrect IBAN code, following are the possibilities: 1. Bank may reject the transfer 2. Send the payment to the wrong branch or account (if check digits are valid but details are incorrect) 3. Charge return or investigation fees (cross-border refunds can take several business days).
No. IBANs are required only in countries that have adopted the IBAN standard. This includes most of Europe and several Middle Eastern and African countries. Many major economies including the US, Canada, India, and Australia do not use IBANs.
