House Bill 308 amends Tennessee Code Annotated to allow counties with populations over 900,000 to levy a sales tax at a rate of three and three-quarters percent (3.75%). This new tax rate can be implemented through a resolution by the county's legislative body and is intended to generate revenue exclusively for the construction of a new county jail or to retire related debt. The bill stipulates that the revenue from this tax increase must be allocated for these purposes for a period of eight years or until the debt is fully retired, whichever comes first. After this period, the tax rate will revert to two and three-quarters percent (2.75%).

Additionally, the bill specifies that any revenue generated from the previous tax rate increase to two and three-quarters percent (2.75%) must be allocated to the county sheriff's department for various expenses, ensuring that this funding is supplemental to existing appropriations. The provisions of this bill are designed to prioritize the funding for law enforcement and jail construction in large counties, reflecting the needs of growing populations. The act will take effect upon becoming law.