CBU

CBU (Clave Bancaria Uniforme) is the standard identifier for bank accounts in Argentina, regulated by the BCRA. It has 22 digits split into two blocks of 11, each with its own check digit. Structure: - Block 1 (8 digits): bank code (3) + branch (4) + check digit (1). - Block 2 (14 digits): account number (13) + check digit (1). Both check digits are computed with a variant of the Luhn algorithm (modulo 10) using specific weights. Validating the CBU rules out trivial errors before initiating a transfer or direct debit. CBU is for traditional bank accounts. Virtual accounts (Mercado Pago, Ualá, Brubank) use CVU — an identifier with the same length and structure, but managed by the BCRA outside the classic banking rails. For PIX payments or international transfers, the bank alias or IBAN are used respectively. Normadata validates CBU by checking length, charset, and both check digits via modulo 10. It does not query account ownership or balance.