HB 4648 prohibits ad valorem (property) taxes in Texas and replaces them with a statewide uniform sales tax. It bans all property taxes at the state and local level beginning January 1, 2026, except for school district debt service taxes, which are phased out by 2033. It increases the state sales tax to 15% and expands its application to all services. The bill creates a state-run funding model for schools and local governments, replacing local tax revenue with state appropriations. It also eliminates local sales taxes and repeals various tax provisions in the Education Code and Tax Code.