Did you request an automatic 6-month extension to file your 2017 tax return back in April? If so, time is running out. For most people who requested an extension, the deadline is Monday, October 15. The IRS reports that roughly 14 million taxpayers requested extensions. Taxpayers can use Direct Pay to make free online payments on their tax bills from their checking or savings accounts. And calendar-year corporate taxpayers that requested a 6-month filing extension to file their 2017 corporate income tax returns also must file their returns on or before 10/15/18.