What should you do if you can't pay your taxes? You must file a return regardless.

If you fail to file and you owe money, the IRS charges a penalty rate that works out to be 60% a year. But for those who file and can't afford to pay, it's only around 6% a year.

So you ignore filing -- or at least filing for an extension -- at your own peril. Just file and pay whatever you can. If you can pay the remainder within four months, you'll usually only incur a minimal penalty.

If you expect it will take longer than four months to pay what you owe, you'll need to file Form 9465 at IRS.gov.

As long as you propose a reasonable payback time, usually before the end of the year, your 9465 will be easily approved.

And here's a little trick: If you propose a payment plan and just keep sending money, your outstanding balance may be paid off before the IRS even has a chance to accept or decline your 9465.

The costs associated with filing a 9465 can be anywhere from $52 (for those who want to e-pay) to $105 (to pay by monthly check). There are also discounts for those with lower incomes.

What if the amount you owe is so large that you can't even begin to think about paying? You still file your return. (Editor's note: Anyone notice a trend here?) The penalties are so huge for failure to file and so light for failure to pay so long as you file.

Meanwhile, consider this: If you put what you owe on your credit card, you'll pay a convenience charge of around 2.75%, plus interest to the credit card company on any balance you carry. That's guaranteed to be much higher than what you would pay the IRS.

Finally, Turbo Tax customers who were filing last minute over the weekend got a little surprise!