Ala. Code § 45-57-244.36: Penalty.

Any person who fails to pay the tax herein levied within the time required by this subpart, in addition to the tax, shall pay a penalty of 10 percent of the amount of tax due, together with interest thereon at the rate of one percent per month or fraction thereof, from the date at which the tax herein levied became delinquent, that is, due and payable, the penalty and interest to be assessed and collected as part of the tax. Provided the county commission, if a good and sufficient reason is shown, may waive or remit the penalty of 10 percent or a portion thereof.