(a) Every corporation organized, incorporated, qualified, or registered under Alabama law or doing business in Alabama as of the first day of a calendar year shall file a return with the department. The return is due not later than March 15 of each year or, in the case of a taxpayer not in existence, not qualifying to do business, or not doing business in Alabama on January 1 of the taxable year, two and one-half months after the taxpayer either comes into existence, qualifies or registers to do business, or commences doing business in Alabama. In cases where receivers, trustees in bankruptcy, or assignees are operating the property or business of taxpayers, those receivers, trustees, or assignees shall file returns for the taxpayers in the same manner and form as the taxpayers are required to file returns. Any tax due on the basis of returns filed by receivers, trustees, or assignees shall be collected in the same manner as if collected from the taxpayers for whose business or property they have custody and control. The department may grant a reasonable extension of time for filing returns under rules and regulations prescribed by the department. No extension shall be for more than six months.

(b) The shares tax provided in this article shall be reported on forms and in the manner as prescribed by the department. The failure to receive a form from the department shall not relieve a taxpayer from liability for any tax, penalty, or interest otherwise due. The tax due, as reported, shall constitute an admitted liability for that amount. The department may compute and assess additional tax, penalty, and interest against a taxpayer as provided in Chapter 2A. Interest on overpayments of shares tax will be computed and paid in the manner provided in Section 40-1-44(b)(1)b.

(c) A corporation that is a member of an Alabama affiliated group that has elected to file a consolidated return pursuant to Section 40-18-39, if it is subject to the shares tax imposed by this article, shall file a separate return reporting and paying the tax as provided in this article without regard to other members of the affiliated group.