The IRS allows individual taxpayers an automatic extension of time (until October 15) to file their tax return, so long as Form 4868 is filed on or before April 15. There are penalties for late filing that will accrue if you do not file the extension form by April 15, or if you ultimately file after the October 15 extension date. Even if you cannot afford to pay the full amount of the tax owed, you should still file your return timely to prevent the accumulation of any additional penalties.