Alabama Code Title 45. Local Laws § 45-19-82.24

To prevent motor vehicles from escaping taxation and to provide for a more efficient procedure for assessment and collection of taxes due, the judge of probate shall not issue any licenses to operate motor vehicles on the public highways of this state, nor shall any transfer be made by the judge of probate until the ad valorem tax on the vehicles has been paid to the county for the preceding year as evidenced by receipt from the judge of probate. No motor vehicle which is owned by a resident of the county or by a business located in the county, or which is otherwise located in the county for licensing purposes, may be operated on the public highways of Alabama unless the motor vehicle has been returned to the tax collector for ad valorem tax purposes. The judge of probate shall issue a certificate of assessment on a form prescribed by the State Department of Revenue, shall collect the taxes shown, and shall make a duplicate of the tax receipt and keep same on file in his or her office. The license tag shall be evidence of the payment of the license and ad valorem tax due as provided under this subpart.