So you owe the IRS back taxes? Here are a few tips to help you with your situation: DON'T put the letters in a drawer and hope they will go away.
They won't.
Open the letters and see what they want.
You may feel helpless and frightened and think you can't pay anything, especially in these tough economic times.
You will feel so much better when you look at your reality and move toward a resolution.
If it's a "demand" (that you pay) letter, you have several ways to proceed.
If you are behind on your personal income taxes, those may be discharged in bankruptcy.
If you don't want to (or can't) file bankruptcy, consider a payment plan.
A payment plan has several benefits to you.
Upon acceptance of your plan, the IRS ceases all collection action, stops seizures of your cars, home or garnishment of your wages and/or bank account and the interest and penalties stop accruing (you have to ask to be sure it's being done).
When you submit a request to the IRS for a payment plan, you will have a better chance of success if you:

1. Make the offer so that the IRS will be paid off in 2-5 years.
   
2. The monthly payment you offer must be equal to or greater than what the IRS figures they could collect from you with a negotiated agreement held in their offices.
   
3. The monthly payment you offer must be based on existing IRS criteria: Subtract household living expenses from your total income.
   Send the difference to the IRS.
   
4. Make the payments.
   If an emergency occurs, making a payment impossible, contact the IRS immediately and work out an alternate arrangement.
   

There are several companies that will negotiate with the IRS for you for a fee.
Make sure they offer to do the above for you and that they don't make wild promises.
That's unrealistic and all they will do is fraudulently take your money.