IMPORTANT DEADLINE: Individuals, or Corporations, S-Corps, Large Partnerships, Partnerships and Trusts
September 16
INDIVIDUALS AND/OR CORPORATIONS: Make a payment of your 2019 estimated tax if you’re not paying your income tax for the year through withholding (or won’t pay in enough lax that way). Use
Form 1040-ES. This is the third installment date for estimated tax in 2019. For more information,
see Pub. 505.
S-CORPORATIONS:File a 2018 calendar year income tax return (Form 1120S) and pay any
tax, interest, and penalties due. This due date applies only if you timely requested an automatic 6-month extension of time to file the return. Otherwise, see Mars, earlier. Provide each shareholder with a copy of their final or amended Schedule K-1 (Form 1120S) or substitute Schedule K-1 (Form 1120S).
PARTNERSHIPS & LARGE PARTNERSHIPS: File a 2018 calendar year return (Form 1065). This due date applies only if you timely requested an automatic 6-month extension. Otherwise, see March 15, earlier. Provide each partner with a copy of their final or amended Schedule K1 (Form 1065) or substitute Schedule K-1 (Form 1065)
C-CORPORATIONS: Must file completed 2018 tax return if a 6-month extension was filed in April.
INTERNATIONAL: Final extended deadline to file Form 8804 if a 6-month extension was filed in March