Ala. Code § 40-18-9
If, in the case of a taxpayer owning any noninterest-bearing obligation issued at a discount and redeemable for fixed amounts increasing at stated intervals, the increase in the redemption price of such obligation occurring in the taxable year does not, under the method of accounting used in computing his net income, constitute income to him in such year, such taxpayer may, at his election made in his return for any taxable year beginning after December 31, 1942, treat such increase as income received in such taxable year. If any such election is made with respect to any such obligation it shall apply also to all such obligations owned by the taxpayer at the beginning of the first taxable year to which it applies and to all such obligations thereafter acquired by him and shall be binding for all subsequent taxable years, unless upon application by the taxpayer the Commissioner of Revenue permits him, subject to such conditions as the Commissioner of Revenue deems necessary, to change to a different method. In the case of any such obligations owned by the taxpayer at the beginning of the first taxable year to which his election applied, the increase in the redemption price of such obligations occurring between the date of acquisition and the first day of such taxable year shall also be treated as income received in such taxable year.
In the case of any obligation of the United States or any of its possessions or of a state or territory, or any political subdivision thereof, or of the District of Columbia, issued on or after March 1, 1941, on a discount basis and payable without interest at a fixed maturity date not exceeding one year from the date of issue, the amount of discount at which such obligation is originally sold shall not be considered to accrue until the date on which such obligation is paid at maturity, sold or otherwise disposed of.
Ala. Code § 40-18-9 (1975)