Did you receive a “Notice of Demand for Payment” ? Once you receive it you have 90 days to petition, in writing, a letter of protest requesting an appeal hearing.
It's on your shoulders... Of course since you are appealing the IRS decision you better have some very good evidence to dispute their claim. So I hope you've saved all of your receipts, documents, bank statements, employer statements, etc.
The Statute of limitations is 10 years to collect the back taxes. But watch out. If you file an Offer in Compromise or File for Bankruptcy the Statute of Limitations can be extended. And let me be honest with you, IRS Hitmen are still likely to contact you about your debt even after the statute has expired. Why? Because most people don't know when the statues have “officially” run out.
If the IRS is trying to implement a Levy or a Lien, they're required to send advance notice. This is so you have the chance to voluntarily pay what you owe before the Hitmen roll up their sleeves and get nasty.
Sometimes, the letters go to the wrong address. If the IRS sends notices to the last known address you have on file, they are not breaking the law. It's essential to keep the IRS updated on your new address. If you move, complete Form 8822 (“Change of Address”).
The Clock is Ticking: Your time is running out. If you've already received collections notices from the IRS you have to act fast. You only have a small window of time to get busy. If you don't, you risk the IRS issuing Levies, Liens, and Seizures. Do your research and stay one step ahead of the game.