HB 250 amends various sections of the Texas Tax Code, Education Code, and Water Code related to ad valorem tax rate calculations for taxing units, including voter-approval tax rates and the process for approving rates that exceed certain thresholds. Specifically, HB 250 standardizes the calculation of voter-approval and no-new-revenue tax rates, revising formulas to account for current debt and sales tax adjustments and making adjustments for special taxing units. It also repeals several existing provisions that allowed specific exemptions or additional calculations in determining tax rates for school districts and certain other entities. This bill will take effect on January 1, 2026​.