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.
BBAN Number - dCode
Tag(s) : Checksum
dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!
NB: Do not confuse with IBAN. This tool checks BBAN, for full IBAN numbers, dCode has a tool for that:
A BBAN (Basic Bank Account Number) is a number identifying a bank account in a country. It is composed of 10 to 30 characters, depending on countries, these characters include 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).
French BBAN number: 12345 12345 0123456789A 03
It is not possible to verify that a BBAN exists with certainty (that is to say, that there is indeed a bank that contains this bank account and that account is active, with money on it), indeed, only banks know their account numbers and associated RIBs and this data is a banking secret. On the other hand, it is possible to check that a RIB is technically valid (that is to say that it does not contain an error in its digits / characters) thanks to the control key which is integrated into the BBAN and which therefore allows a partial verification. If the validation fails, then the RIB is necessarily false/erroneous.
The algorithm for the validation calculator 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
|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
Example: $ 12345123450123456789100 \mod 97 \equiv 94 $ and $ 97 - 94 = 3 $
The checksum key is therefore 03 (the key removed previously), the BBAN is valid.
Why 97? Because it is a prime number (the largest with 2 digits) that will minimize the errors.
Reminder : dCode is free to use.
The copy-paste of the page "BBAN Number" or any of its results, is allowed (even for commercial purposes) as long as you cite dCode!
Exporting results as a .csv or .txt file is free by clicking on the export icon
Cite as source (bibliography):
BBAN Number on dCode.fr [online website], retrieved on 2023-12-03,