Poor you. You slave over your taxes, hating every minute of it, but knowing you'll get a nice reward at the end when you see how big your refund will be.

Then what happens? No refund. The Internal Revenue Service wants YOU to pay THEM. The nerve.

Worse: You don't have the money.

There are lots of ways this could happen. Suppose you were laid off and collected unemployment insurance. That's taxable, and Missouri doesn't automatically deduct the taxes.

You might have raided your 401(k) plan to pay the rent. The withdrawals are taxable, and there's a 10 percent penalty if you're under 59 ½ years old.

"That's really bad. Not only do you lose your job, but you owe taxes," says Serita Eldridge, president of the Missouri Society of Enrolled Agents - people approved by the IRS to represent citizens in tax cases.

Or suppose you had some big wins at the slots. Uncle Sam wants his cut.

People who start small businesses sometimes misunderstand the law and get nailed come April. Workers cobbling together a living out of several part-time jobs sometimes discover that too little money was withheld for taxes.

No matter why, you may have to stiff the IRS come April.

So, let's look at ways to fend off the tax man until you can pay up. We'll also review ways to beg for mercy if you owe so much that you can't possibly pay ever. (Good luck with that.)

First, file your tax return even if you can't pay. The penalty for not filing is much bigger than that for not paying. If you don't file, the IRS will fine you 5 percent per month, compounded monthly, plus interest at 6 percent per year, also compounded monthly on your unpaid taxes.

If you file but don't pay, the IRS will want a one-time penalty of 5 percent, plus six percent annual interest compounded monthly.

So, send in whatever money you can spare to keep the cost down.

You can set up an installment plan by filling out an IRS form. Suggest a payment you can afford - defaulting on the IRS is a bad idea.

If you can pay it all off within 120 days, the plan is free. Need longer and you'll pay a $52 set-up fee if you let the government tap your bank account for the payments, or $105 if you don't. There's a lower fee for low-income people.

The IRS does have a heart, albeit a small and stony one. If you've been knocked flat by life, you can file for an "Extension of Time for Payment of Tax Due to Undue Hardship." You'll have to list your assets and expenses, and explain the personal disaster that befell you. Death often counts. Serious illness might.

If you appear pitiful enough, the IRS may waive penalties, although interest will still run.

If you are extremely and hopelessly pitiful, you can make an "Offer in Compromise." You offer to pay part of what you owe, if the IRS forgives the rest.

Forgiveness is limited among tax collectors. The IRS rejects three out of four compromise applications.

The program works best for people in dire straits - those too sick to work or needing expensive medical care. The IRS calculates how much it can squeeze out of you over the next few years if you sell what you own and subsist on a spartan budget dictated by the government. If you offer that amount, the IRS may take it.

The IRS doesn't give a hoot about your other debts. It costs $150 to apply, and the taxpayer must make a partial tax payment with the application.

"If you have to owe money, the IRS is not the person you want to owe money too," says Mark Luscombe, tax analyst at CCH Inc., the tax analysis and software company.

If your IRS debt is three years old, you might be able to dump it by going bankrupt, says Luscombe.

There's no reason for panic if you can't pay on time. "The IRS doesn't come after you with full force," says Eldridge. "They'll tell you exactly what they're going to do before they do it."

Above all, the IRS doesn't like to be ignored. Answer their letters promptly. If you're attempting to pay, they are much less likely to get nasty and file liens and garnishments.