Nowadays Brazilian Ministério da Fazenda promotes the electronic interaction with taxpayers in order to avoid the necessity of personal visits to its offices. For this purpose e-CNPJ is introduced. This digital certificate identifying electronic documents sent by companies to taxation agency is available in two forms: A1 and A3. A1 type is cheaper (approx. R$ 130) and valid only for 1 year. A3 is 2-4 times more expensive but can be used 3 years. A3 e-CNPJ is more secure as it contains cryptographic application in the smart-card or token. A1 e-CNPJ is just computer files.
Use CNPJ Consulta web-form from the Secretaria da Receita Federal site to query company information by CNPJ. Provide only decimal digits (without dividing dots, slash, hyphen) into CNPJ input box there and press Consultar button.