🇦🇷 ARGENTINA · BANK ACCOUNT
CBU validator (free)
The CBU (Clave Bancaria Uniforme) is the 22-digit Argentine bank account identifier issued by the BCRA. It encodes the bank, branch and account number with two independent Mod-10 check digits. This tool validates both blocks client-side.
Validates locally — your data never leaves your browser. No tracking on input. Format and check-digit validation only.
Validates locally — your data never leaves your browser. No tracking on input.
How CBU validation works
A CBU has 22 digits split into two blocks. Block 1 (8 digits): bank code (3) + branch code (4) + check digit (1). Block 2 (14 digits): account number (13) + check digit (1). Each block is validated independently.
Block 1 check digit: multiply the 7 base digits by weights [7,1,3,9,7,1,3], sum, take mod 10, then 10 − mod (or 0 if mod is 0). Block 2 check digit: weights [3,9,7,1,3,9,7,1,3,9,7,1,3] applied to the 13 base digits, same Mod-10 derivation.
Bank code 000 is reserved for CVU (virtual accounts) and is rejected for CBU. This tool does not verify that the bank, branch or account is currently active — that requires a query to the BCRA or the issuing bank.
Frequently asked questions
What's the difference between CBU and CVU?
CBU is for traditional bank accounts; CVU (Clave Virtual Uniforme) is for virtual accounts at fintechs (Mercado Pago, Ualá, Brubank, etc.). Same 22-digit format and same Mod-10 algorithm, but CVU always starts with 000 as the bank code.
Does this validator confirm the account exists?
No. Format and check-digit validation only. Confirming account existence requires a query to the BCRA's debin/transfer authorization system, which is not publicly accessible.
Can I use this for CCI (Peru) or CLABE (Mexico)?
No. Each country has its own bank-account scheme with different lengths and algorithms. The CBU validator works only for Argentine CBU; the Normadata Verify API supports CCI, CLABE, CBU and CVU.
Can I validate CBU via API?
Yes. Normadata's Verify API validates CBU server-side with the same two-block Mod-10 algorithm, plus bank-identification metadata.
Want CBU validation in your app?
The Normadata Verify API validates CBU, CVU, CLABE, CCI and 20+ Latin American bank-account identifiers with a single JSON call.
See the Verify API→