October 17 — Personal returns that received an automatic six-month extension must be filed today and any tax, interest, and penalties due must be paid.

·   Electing large partnerships that received an additional six-month extension must file their Forms 1065-B today.

·   If the monthly deposit rule applies, employers must deposit the tax for payments in September for Social Security, Medicare, withheld income tax, and nonpayroll withholding.

October 31 — The third quarter Form 941 (“Employer’s Quarterly Federal Tax Return”) is due today and any undeposited tax must be deposited. (If your tax liability is less than $2,500, you can pay it in full with a timely filed return.) If you deposited the tax for the quarter in full and on time, you have until November 10 to file the return.

·   If you have employees, a Federal Unemployment Tax Act (FUTA) deposit is due if the FUTA liability through September exceeds $500.

November 15 — If the monthly deposit rule applies, employers must deposit the tax for payments in October for Social Security, Medicare, withheld income tax, and nonpayroll withholding.

December 15 — Calendar-year corporations must deposit the fourth installment of estimated income tax for 2015.

·   If the monthly deposit rule applies, employers must deposit the tax for payments in November for Social Security, Medicare, withheld income tax, and nonpayroll withholding.