Stuff happens, and here it is April 18 — tax deadline day — and you have yet to file your tax return.

You have a couple of options. You can:

  1. File for an extension and put off the inevitable for six more months.
  2. Or you can get it done in the final hours remaining.

How an extension works

The IRS will wait for your return until Oct. 15 (Oct. 16 this year, since the 15th lands on Sunday) if you file for an automatic extension. You can do this by sending in Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return. You can e-file the extension request from your home computer or have your tax professional who is an IRS-authorized e-filer do it for you.

The extension request must be made before the Tax Day deadline passes, or postmarked April 18 if you snail-mail it.

While the extension will give you six more months to get your tax act together, you don’t have to wait until that ultimate deadline. Anytime you get your tax-filing material in order before then, you can send in your 1040.

But do pay your taxes on time

Filing this form won’t delay any taxes you owe. If you don’t send the taxes due, you’ll get hit with penalties.

In the worst-case scenario — for those who both fail to file and fail to pay — penalties can amount to your tax bill plus an additional 47.5 percent of the unpaid tax — plus interest.

How do you know how much money to send? You don’t have to be precise. As long as the amount comes to 90 percent of what you eventually owe, you’ll be OK with the IRS.

The easiest way to estimate what to pay is to look over last year’s tax return. If your financial and tax situation are basically the same as last year — you have the same job, still married, two kids, deductible mortgage interest — then what you owe this year is likely to be close to the amount you owed last year.

Hardship relief

What if you are experiencing severe financial hardship? First consider the IRS’ three payment options to see if they might work for you.

In rare cases, the IRS offers some penalty relief to taxpayers who would face an undue hardship if they pay their tax bills by the deadline. This relief applies to income taxes, as well as to self-employment taxes.

You must send the IRS supporting documentation that shows you would have a substantial monetary loss, such as selling property at a much lower price than you could get under ideal circumstances, if you pay your tax on time.

In these cases, the IRS may waive the late-payment penalty if the eligible taxpayers pay tax and interest due by Oct. 15. However, interest on the due tax will continue to accrue. To apply for penalty abatement, file Form 1127, Application for Extension of Time for Payment of Tax Due to Undue Hardship.

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Filing at the last minute

If you decide it’s just as easy to file your taxes before the midnight deadline and be done with them, follow this quick guide:

  • First step is to pick which form to use. The IRS gives you three options: the 1040EZ, the 1040A and the long 1040. Use one of the latter two if you might be eligible for certain tax breaks available on page 1 of those forms.
  • If your tax situation is simple, you might want to file Form 1040EZ. Check out Bankrate’s 1040EZ tax form calculator!
  • Next, track down all your income documents — W-2 salary, wage statements, reports on how much interest you earned last year.
  • If you’re missing your W-2, use the data on your final pay stub from last year to complete Form 4852, the IRS’ authorized income statement substitute.
  • For interest and dividend income, you can pull out your last account statements if you can’t find the 1099 forms or tax statements that were sent to you. Your statements should have the earnings information you need.
  • Determine which tax deductions or credits you can claim. The bulk of the tax breaks, such as home-related deductions, go to itemizers. But most filers actually claim the standard deduction.
  • Now it’s time to fill in the form blanks. You can download one of several tax software packages and use it to file electronically directly from your personal computer. Or, you can access essentially the same products online to complete your taxes via the Web. The IRS encourages this method via the Free File Alliance, which affords many taxpayers no-cost online tax prep and filing.

If you do your taxes the old-fashioned paper way, mail your return before midnight. Use the U.S. Postal Service’s post office locator to find the one nearest you. If it’s getting late, call first to make sure the office will be open longer to collect tax returns.

Whether you file for an extension or file your return, just be sure to send the IRS something.

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