Receiving an IRS audit letter
In sending out audit letters, the Internal Revenue Service will occasionally make a mistake. Still, most often than not, the taxpayer has relocated and has yet to inform the IRS of their new address.
If the IRS can prove it sent the letter to the last known address, it has satisfied the law.
The other possibility is that the taxpayer ignored or accidentally discarded the IRS letter. In either case, the IRS can conduct its audit without the taxpayer knowing it.
Suppose the audit concludes you owe money to the IRS. In that case, it is authorized to commence its collection process against you and begin seizing assets.