Need. According to Article 5 of the newly revised Individual Income Tax Law of People's Republic of China (PRC), natural taxpayers need to provide the taxpayer identification number to the tax authorities or withholding agents when handling tax-related matters, such as tax declaration, tax payment, tax refund application, issuance of tax payment vouchers, tax inquiry, etc. Therefore, they need to provide the identification number when reporting tax-related illegal facts. The taxpayer identification number is the number on the tax registration certificate, and the taxpayer identification number of each enterprise is unique.