According to the website of the Department of Revenue, the due date of a business privilege tax return of a C-corporation with a fiscal year end date other than June 30 is 3.5 months after the beginning of the taxable year.  The 2018 Form CPT for a calendar year C-corporation is due April 17.  For C-corporations with a fiscal year ending June 30, the 2018 Form CPT is due September 17.  For limited liability entities, the business privilege tax return is due 2.5 months after the beginning of the taxable year.  The 2018 Form PPT for a calendar year limited liability entity is due March 15.  The due date for a business privilege tax return for financial institution groups corresponds to the due date for the Alabama Financial Institution Excise tax return. The return is due 3.5 months after the beginning of the taxable year or April 17.

Alabama – LLC Business Privilege Tax Returns Due March 15