The Internal Revenue Service today urged taxpayers whose tax-filing extension runs out on Oct. 15, to double check their returns for often-overlooked tax benefits and then file their returns electronically using IRS e-file or the Free File system.About a quarter of the 13 million taxpayers who requested an automatic six-month extension this year have yet to file. Although Oct. 15, is the last day for most people, some still have more time, including members of the military and others serving in combat zone localities who typically have until at least 180 days after they leave the combat zone to both file returns and pay any taxes due.“If you still need to file, don’t forget that you can still file electronically through October 15,” said IRS Commissioner John Koskinen. “Many people may not realize they may be eligible to use Free File available on IRS.gov/freefile.