Relating to the authority of a property owner to obtain an injunction restraining the collection of ad valorem taxes by a taxing unit if the taxing unit adopts a tax rate that exceeds the voter-approval tax rate and subsequently takes an action that constitutes a material deviation from the stated purpose of the tax increase.

HB 3879 allows property owners to seek court injunctions to stop a taxing unit (like a city or county) from collecting property taxes if that unit later changes how the taxes are used in a way that materially deviates from the purpose voters approved when they authorized the tax increase. The bill defines "material deviation" to include significant changes in purpose, financing, costs, or scope beyond 33%, or legal findings that the tax purpose violated law. If a property owner successfully challenges the deviation, they can get a refund of taxes paid plus attorney fees without needing to apply to the tax collector. This directly affects property owners who can legally block tax collections and taxing units that must adhere strictly to voter-approved tax purposes.