The deadline to file your federal income tax returns is next Monday, 18 April 2016. If you're one of the thousands of Americans who aren't going to be done by Monday, you should file an Application for Automatic Extension of Time To File U.S. Individual Income Tax Return. There are three ways to apply for a tax extension, so one should work for you. Most importantly, don't forget that an extension of time to file is not an extension of time to pay. If you anticipate that you owe additional tax beyond the amount withheld from your pay, you need to submit a payment with your application for tax extension, or risk accruing interest and penalties.
How To File for A Tax ExtensionThe Application for Automatic Extension of Time to File U.S. Individual Income Tax Return is IRS Form 4686. The form itself has basic directions for filing by mail, electronically, or by making a payment. (It's a little weird, but just making a payment actually has the effect of giving you an extension. Go figure.)
If you owe, I think the easiest way to file for a tax extension is to make your payment electronically at www.irs.gov/payments. After that, I prefer paper, but that's just me and you don't get an immediate confirmation if you send it by mail. To file electronically, and get a confirmation, you will have to use one of the FreeFile providers available through the IRS website. Using one of these FreeFile providers to process your application for extension does not obligate you to use that provider for your actual tax return filing.
Automatic Extensions for Taxpayers Living AbroadU.S. taxpayers who are permanently living abroad, or are posted abroad with the U.S. military, are granted an automatic two month extension of time to file and time to pay. No form is required for this extension.
Automatic Extensions for Taxpayers in a Combat ZoneMilitary members who are unable to file their tax return due to service in a combat zone or contingency operation are automatically granted an extension of at least 180 days after leaving the eligible area. The math is a little complicated, but explained thoroughly in IRS Publication 3, Armed Forces Tax Guide. This extension applies to both the service member and their spouse.
Extensions for State Income Tax ReturnsDon't forget that individual states have different rules for extensions of time to file, and different tax filing deadlines. Do not assume that your federal extension means that you'll be good with the state(s) in which you file.
Since tax day is still six days away, you may find that the act of estimating whether you need to make a payment gets you close enough to just finish the darn tax return. Wouldn't that be great? If that isn't going to happen, do the next best thing and get that extension filed, make payment as necessary, and be sure to file your final return by 18 October 2016.