Group 1 - The core concept of the article is the importance of the real estate unit number, which serves as a unique identifier for real estate information, akin to an "ID card" for properties [2] - The real estate unit number consists of several components: a 6-digit area code, an 8-digit project number, a 4-digit building number, and a 10-digit room number [4] - The real estate unit number can typically be found on the real estate registration certificate under the "real estate unit number" section [6] Group 2 - To enter the real estate unit number in the electronic tax bureau, users must first log into the system [7] - Users should navigate to the "Property and Behavior Tax Source Collection and Consolidated Declaration" module and click on "Add Tax Type" [8] - After selecting the appropriate tax type, such as "Urban Land Use Tax" or "Property Tax," users can proceed to the tax source collection interface [10][11] - When entering information, if the property certificate type is "Real Estate Certificate," the real estate unit number must be filled in as a mandatory 28-character field [14] - Once all information is confirmed to be correct, users can click "Submit" to successfully complete the tax source collection [15]