Third quarter 2013 individual estimated tax is due.

Deadline for partnerships, S corporations and LLCs to issue K-1 forms.

Final deadline to file corporate tax returns if an extension was requested. (Forms 1120, 1120A, 1120S).

Final deadline to file trust income tax returns (Form 1041) if an extension was requested.

Final deadline to file partnership tax returns (Form 1065) if an extension was requested.