Support upcoming alphanumeric CNPJ format (effective July 2026)

[dmg-vicente]

Brazil’s Receita Federal has announced recently that CNPJ will support an alphanumeric format starting July 2026.

Currently the CNPJ validation logic (specifically ptBrCheck in isTaxID.js) assumes numeric-only inputs.

With the new format:

• letters will become valid characters in CNPJ values
• existing numeric-only validation will reject valid CNPJs

Example:

Current format (numeric-only):
12.345.678/0001-95

New format (alphanumeric, same mask):
12.ABC.345/01DE-35