# BLOG

- [What is CNPJ](/en/blog/o-que-e-cnpj.md): The National Register of Legal Entities is the registration used by the Federal Revenue to open an institution with or without profit purposes
- [Alphanumeric CNPJ](/en/blog/alphanumeric-cnpj.md): How to calculate the check digits of an alphanumeric CNPJ (Brazilian company registration number)
- [Consult CNPJ with Java](/en/blog/consultar-cnpj-java.md): Learn how to consult company data through the CNPJ using the CNPJ.ws API, with data from Receita Federal, Sintegra, and Suframa using Java.
- [Consult CNPJ for Free with Excel](/en/blog/consultar-cnpj-excel.md): Use this Excel spreadsheet to consult company data through the CNPJ using the CNPJ.ws API, with data from Receita Federal, Sintegra, and Suframa.
- [Consult CNPJ with PHP](/en/blog/consulta-cnpj-php.md): Learn how to consult company data through the CNPJ using the CNPJ.ws API, with data from Receita Federal, Sintegra, and Suframa using PHP.
- [Trigger to Consult CNPJ in Protheus](/en/blog/gatilho-consultar-cnpj.md): Trigger to consult CNPJ in the registration of customers or suppliers in Protheus using ADVPL and the CNPJ.ws API with data from Receita Federal, Sintegra, and Suframa.
- [Keep Customer and Supplier Records Updated](/en/blog/manter-clientes-fornecedores-atualizados.md)
- [Consult CNPJ with Javascript and Node.JS](/en/blog/consultar-cnpj-javascript.md): Learn how to consult company data through the CNPJ using the CNPJ.ws API, with data from Receita Federal, Sintegra, and Suframa using Javascript/Node.js
- [Consult CNPJ with ADVPL (Protheus)](/en/blog/integracao-protheus.md): Consult CNPJ in Protheus using the CNPJ.ws API with ADVPL
- [CNPJ.ws Project](/en/blog/cnpjws.md)