CNAE Format Validator
Validate the format of a Brazilian CNAE 2.3 code (7 digits, e.g. 6201-5/00), the national classification of economic activities. Useful for business setup.
CNAE subclass: the 7-digit economic activity code NNNN-N/NN
The CNAE (Classificação Nacional de Atividades Econômicas) is the official Brazilian classification of what a business does, maintained by the IBGE through the CONCLA commission. Its most detailed level, the subclasse, is a 7-digit code written NNNN-N/NN — for example 6201-5/00 (custom software development). This tool checks that structural format.
The CNAE descends from the international ISIC standard but adds two extra digits (the /NN subclass) for Brazilian fiscal detail. Every CNPJ declares a main CNAE plus optional secondary ones, and that choice drives tax regime, Simples Nacional eligibility, licensing and inspection requirements.
Anatomy of 6201-5/00
- Division (
62): the first two digits — broad sector (here, IT services). - Group & class (
620,6201): progressively narrower activity. - Check digit (
5): the fifth digit (-5) is a verifying digit on the class. - Subclass (
/00): the Brazilian two-digit detail;00means no further breakdown.
Where it matters
- CNPJ registration: the main CNAE is mandatory and shapes everything downstream.
- Tax regime: some CNAEs are barred from Simples Nacional or trigger ICMS substituição tributária.
- Licensing: environmental, sanitary (ANVISA) and fire-department requirements key off the CNAE.
- Mock data / testing: validating the
NNNN-N/NNmask before a Receita/IBGE lookup.
Common pitfalls
- Format ≠ exists: a well-masked code may not be a real CNAE — check the IBGE/CONCLA table.
- Punctuation is cosmetic:
6201500and6201-5/00are the same; normalise before comparing. - Wrong CNAE = wrong tax: misclassifying activity can exclude you from Simples or attract the wrong ISS/ICMS.
- Main vs secondary: a company can hold many CNAEs; don't assume the first is the only one.
FAQ
Why does CNAE have 7 digits when ISIC has fewer? Brazil appended a 2-digit subclass for finer fiscal granularity beyond the international class.
What is the fifth digit? A check digit on the four-digit class, separated by a hyphen (6201-5).
Can one company have several CNAEs? Yes — one main CNAE plus any number of secondary CNAEs on the CNPJ card.
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