Ala. Code § 40-18-78

The amount deducted and withheld as tax under Section 40-18-71 during any calendar year upon the wages of any individual shall be allowed as a credit to the recipient of the income against the tax imposed by Section 40-18-5 for taxable years beginning in such calendar year. If more than one taxable year begins in such calendar year, such amount shall be allowed as a credit against the tax for the last taxable year so beginning.