If you can’t finish your return on time, make sure you file Form 4868 by April 15, 2013. Form 4868 gives you a six-month extension of the filing deadline until October 15, 2013. On the form, you need to make a reasonable estimate of your tax liability for 2012 and pay any balance due with your request.
Requesting an extension in a timely manner is especially important if you end up owing tax to the IRS. If you file and pay late, the IRS can slap you with a late-filing penalty of 4.5 percent per month of the tax owed and a late-payment penalty of 0.5 percent a month of the tax due. The maximum late filing penalty is 22.5 percent and the late-payment penalty tops out at 25 percent. By filing Form 4868, you stop the clock running on the costly late-filing penalty.