Corporate extension taxes due October 16, 2017March 31, 2017 If a 6-month tax extension was requested/obtained, file a 2016 tax return (Form 1120) and pay any tax due by this date. Share this: Click to email a link to a friend (Opens in new window) Email Click to share on X (Opens in new window) X Click to share on LinkedIn (Opens in new window) LinkedIn Click to share on Facebook (Opens in new window) Facebook Like this:Like Loading... Related