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BBAN Number

Tool to check BBAN numbers. The BBAN (Basic Bank Account Number) checksum algorithm allows to check if a full bank account BBAN number is correct.

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BBAN Number -

Tag(s) : Checksum

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# BBAN Number

## BBAN number checker

This tool checks BBAN and not IBAN numbers (dCode has a tool for that)

## BBAN checksum calculator

Tool to check BBAN numbers. The BBAN (Basic Bank Account Number) checksum algorithm allows to check if a full bank account BBAN number is correct.

### What is a BBAN?

A BBAN (Basic Bank Account Number) is composed of 10 to 30 characters, depending on countries, corresponding to the bank codes (including the account number) and a checksum key.

Example: In France a BBAN/RIB has 23 characters: bank code (5 digits) + counter code (5 digits) + account number (11 digits and / or letters) + RIB key (2 digits between 01 and 97).

### How to verify an BBAN number? (Validity check)

The calculator algorithm checks the BBAN key via a modulo 97:

Example: The bank number is: 12345 12345 0123456789A 03

Step 1: Remove the key BBAN code.

Example: The key is composed of the last 2 digits: 03. The rest of the calculation is done with 12345 12345 0123456789A 00.

Step 2: replace any letters by figures in the table

 A, J 1 B, K, S 2 C, L, T 3 D, M, U 4 E, N, V 5 F, O, W 6 G, P, X 7 H, Q, Y 8 I, R, Z 9

Example: A=1, the BBAN becomes 12345123450123456789100

Step 3: Calculate the value of the result modulo 97, then subtract the result to 97.

Example: $12345123450123456789100 \mod 97 \equiv 94$ and $97 - 94 = 3$

The checksum key is therefore 03 (the key removed previously), the BBAN is valid.

To make this modulo calculation, use a calculator that accepts calculation with large numbers (arbitrary precision) as proposed on dCode.

### Why the modulo 97?

Why 97? Because it is a prime number (the largest with 2 digits) that will allow to minimize the errors.

## Source code

dCode retains ownership of the source code of the script BBAN Number online. Except explicit open source licence (indicated Creative Commons / free), any algorithm, applet, snippet, software (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any function (convert, solve, decrypt, encrypt, decipher, cipher, decode, code, translate) written in any informatic langauge (PHP, Java, C#, Python, Javascript, Matlab, etc.) which dCode owns rights will not be released for free. To download the online BBAN Number script for offline use on PC, iPhone or Android, ask for price quote on contact page !