Code of Alabama
Article 1 - County Voter Registration Lists.
Section 17-4-5 - Notice of Previous Registration to Be Given.

When a person makes application for registration before a county board of registrars, it shall be the duty of that board, if the elector has been previously registered before in any other county or state, to notify the registrar of voters in the county or state of the previous registration that such elector has applied for and been registered as an elector in the county where such application for registration is made. In addition to asking an elector whether he or she has been previously registered before in any other county or state, the board of registrars shall ascertain if an elector has been previously registered before in any other county of this state by conducting a computerized search of the statewide voter registration list, using the elector's name along with any other identifying information provided by the elector.
When the notice required in this section is received by the board of registrars of any county where such person had been previously registered, it shall be the duty of the board of registrars receiving such notice to remove forthwith the name of such person from the list of qualified electors of the county of previous registration, and such person shall thereafter be disqualified to vote in any election held in any county of previous registration unless the person is duly reregistered.