The IRS is required by law to follow specific steps when notifying a tax payer of a tax liability. This is the Collections Due Process. The IRS has to follow these rules step for step. They only need to send notices to the last know address of the tax payer.
The process starts with a balance due notice, form CP14 or CP11. The balance due notice states how much is due and from which tax year.
After 10 days of sending the Balance Due Notice the IRS will send a second notice of demand for payment with form CP 501.
10 days after the CP501, a CP503 is sent with the same demand for payment.
When all the above notices are ignored, the IRS will send a CP504, Notice of Intent to Levy. This is always sent via certified mail.
In most cases a final notice of intent to levy is sent. This is letter L 1058. This step may be skipped by the IRS.
If the taxpayer ignores or fails to respond to all the notices, a Levy is placed against the taxpayer and a notice is then sent to the taxpayer informing them of the levy. The Levy Notice is form 668.
If you are in IRS collections, you may need help to handle the IRS. You want to act quickly when you start receiving these notices and not wait until you are levied which can leave you with no money that may be used to get help. It is always best to be proactive with the IRS. You want to deal with the IRS on your terms not theirs.