Creates the Prohibition of Closed-Door Tax Increases Act. Provides that a unit of local government may not increase a levied tax without authorization by referendum of the electors of the unit of local government. Provides that a referendum to increase a levied tax must include a sunset clause on which the tax increase authorized by the referendum measure shall expire. Provides that, if an increase in a levied tax is intended to generate a cash flow to service a debt, the increase must sunset no later than the date that the debt is scheduled to be paid off, and, if an increase in a levied tax is intended to generate a cash flow that will be spent for purposes other than debt service, the increase must sunset no later than 10 years after the date on which the tax increase begins. Provides that, to the extent the Act conflicts with any other provision of law, the Act controls. Provides that nothing in the Act infringes upon the right of a unit of local government to impose or increase nontax fines or fees. Provides that the Department of Revenue shall adopt rules to enforce the Act. Limits concurrent exercise of home rule taxing powers.