Ala. Code § 40-12-25

Unless otherwise provided, if any business licensed by this title shall commence after April 1 in any year, the amount of the license or privilege tax shall be one half of the year’s license or privilege tax. In all other cases the license shall be taken out for the full term of one year, unless a shorter term is fixed by the provisions of this title. In all cases where the amount of license is rated according to the population of the town, city, or county, the population of such town, city, or county as fixed by the last preceding United States census shall govern.