IRS Uncollectible Status
You can't get blood from a stone or so the saying goes. The IRS recognizes this and if your financial situation shows this to be true, they will check the box "Uncollectable" and set a date a couple of years in the future to revisit your situation.
How can Uncollectible Status work for you?
It gets them off of your back for 18 - 24 months. The IRS does not want to waste resources trying to collect from someone who does not have an ability to pay.
The Statute of Limitations continues to run. This gets you closer to that magic date in which the IRS will have to write-off the debt forever.
The IRS will not take you at your word that you can not pay you tax debts. They will want information on what you own and what you owe to determine your ability to pay. The IRS uses a formula approach call the "Reasonable Collection Potential" or "RCP" to make the determination of how much blood is in that stone.
Knowing how the RCP formula works for your situation can go a long way in getting to Uncollectable Status.