The user name of Guangdong Taxation is the taxpayer identification number (tax number). You need to change your password in time after the first login. If you forget your password, you need to bring the original tax registration to the tax office to change your password. Taxpayers who have applied for digital certificates can log on to the national tax portal to handle tax-related matters. The system is easy to operate, and its main functions include: application for tax-related matters, progress inquiry, download of approval documents, etc.