Calculate Bank Account Number From Iban

An International Bank Account Number (IBAN) is a standardized format for identifying bank accounts across national borders. This guide explains how to extract the bank account number from an IBAN and provides a calculator to perform the conversion.

What is an IBAN?

An IBAN (International Bank Account Number) is an internationally agreed system of identifying bank accounts across national borders to facilitate the communication and processing of cross-border credit transfers. Each IBAN consists of up to 34 alphanumeric characters, including:

Country Code (2 letters)
Check Digits (2 digits)
Bank Account Number (variable length)

The IBAN is structured to ensure accuracy and prevent errors in international transactions. The first four characters are always the country code and check digits, followed by the bank account number.

How to Calculate Bank Account Number from IBAN

To extract the bank account number from an IBAN, follow these steps:

Identify the IBAN structure for your country.
Locate the position where the bank account number begins in the IBAN.
Extract the remaining characters after the country code and check digits.

Note: The exact position of the bank account number varies by country. Always refer to your country's IBAN specification for precise details.

Formula Used

The bank account number can be extracted from an IBAN using the following formula:

Bank Account Number = IBAN.substring(4)

Where:

IBAN is the full International Bank Account Number
substring(4) extracts all characters after the first 4 (country code + check digits)

Worked Example

Let's extract the bank account number from the following IBAN:

Example IBAN: GB33BUKB20201555555555

Identify the country code and check digits: GB33
Extract the remaining characters: BUKB20201555555555

The bank account number is: BUKB20201555555555

Frequently Asked Questions

What is the difference between IBAN and bank account number?

An IBAN is an international standard for identifying bank accounts, while a bank account number is the local identifier used within a country. The IBAN includes the country code, check digits, and the bank account number.

How do I verify the accuracy of an IBAN?

You can verify an IBAN using the IBAN check digits, which are calculated using a specific algorithm. Many banking software and online tools can perform this validation.

Can I use the same bank account number in multiple countries?

No, bank account numbers are typically specific to a country. The IBAN system provides a standardized way to represent bank accounts internationally, but the underlying account number may differ by country.