The Bureau of Internal Revenue (BIR) has the power to ascertain the correctness of the returns filed by the taxpayers and to determine any liability for internal revenue tax. Corollary to such power, the BIR is empowered and has the authority to obtain information, examine documents, and take testimonies of any person.

Pursuant to Section 5 of Republic Act (RA) 8424, as amended (Tax Code), the BIR may inspect the books, records, or other documents of the taxpayer and may collect information such as names, addresses, financial statements, among others. The BIR may also obtain information from any person other than the person whose internal revenue tax is being audited or investigated.