Fill in a user name that is easy to remember and use. The unified user name of the electronic tax bureau refers to the user name that taxpayers fill in when registering with the electronic tax bureau, which is used to log in to the electronic tax bureau for tax declaration and inquiry. The uniform user name of electronic tax bureau is 6-20 characters long, which can include numbers, letters and underscores. The unified user name of the electronic tax bureau must comply with the relevant specifications and cannot contain special characters and sensitive vocabulary. The unified user name of the electronic tax bureau must be unique and cannot be duplicated with the user names of other taxpayers.