If you did not complete your federal tax return by the April 15 deadline and filed for an extension, you have until October 15 to wrap things up.

Taxpayers who needed more time to file their 2008 tax return and bought more time by filing an extension, moved the deadline back six months to October 15, 2009 thus avoiding IRS late-filing penalties.

Plan Ahead to File Late in 2010

If you think you will need more time for filing your 2009 taxes (planning to procrastinate – there’s a good topic for your therapist!) you can do it easily. There’s a catch, though: the extension only pushes back the due date of the paperwork. If you owe money, you need to estimate the amount, then file your extension and make your payment by April 15, 2010.

There are several ways to file your extension, officially known as IRS Form 4868: Application for Automatic Extension of Time to File.

If you’ve already started a return in TurboTax, go back to the TurboTax program and click Apply for more time to file your return on the Get Started page. TurboTax walks you through preparing Form 4868. Then print and mail it in (also including a check if you’ll owe) on or before April 15, 2010. You also can use TurboTax to find out about extensions for state returns.

Alternatively, you can print the form and fill it out by hand. Refer to IRS Form 4868: Application for Automatic Extension of Time to File. Print the form and instructions. Fill out the form and send it to the IRS address for your state.

If you owe federal taxes for 2008, include your payment with your Form 4868 and mail it—postmarked by April 15, 2010. (If you don’t make a payment for the taxes due, you could be liable for penalties and interest, even if you’ve filed for an extension.) Then complete and file your return on or before October 15, 2009.

If you’ve e-filed or mailed Form 4868 and need to pay by credit card, you can use one of several IRS approved Electronic Payment Methods. You can pay with your credit card online or by phone. File your complete return by October 15, 2009.

Be Careful – This is the IRS you are dealing with

If the IRS thinks your estimate is unreasonable, they may disallow your extension and assess a penalty for filing late tax returns.

If you underestimate your taxes, you’ll have to pay interest on whatever amount you fail to pay by April15.

If you pay less than 90 percent of the tax you owe, you’ll end up owing a penalty of 0.5 percent of the underpayment every month until you pay the balance. For example, if you pay $600 on April 15, but discover when you complete your return that you really owe $1,000, you will owe 0.5 percent per month on the $400 that is overdue, or about $2 a month, until you pay the balance in full.

If you live outside the United States, you may be able to get an extension by filing IRS Form 2350: Application for Extension of Time To File U.S. Income Tax Return if you believe you will qualify for special tax treatment. See IRS Publication 54: Tax Guide for U.S. Citizens and Resident Aliens Abroad to learn if this form might help you.

Do you need to request a state income tax extension, too?

State tax extension guidelines vary. To see detailed information about state extension filing deadlines and mailing addresses, select your state of interest from the TurboTax Web site.