Anyone can sue anyone, but the IRS does not need to in order to collect the amounts due them for income tax and the other tax collections it administers.
The IRS has the following collection powers:
None of the above collections activities requires the IRS to go to court. They are all done on the IRS’ own authority. When the IRS does end up in court, it is usually because the taxpayer sues them. They are represented in court by their own in-house attorneys.
In addition, the IRS’ Criminal Fraud Investigation Unit can, and does, prosecute criminal actions in court. This is not exactly a lawsuit. It is worse. It involves putting taxpayers engaged in criminally fraudulent activity in jail and can involve heavy monetary fines, penalties, restitution and disgorgement. Remember: Al Capone did not go to jail for murder and mayhem, he went for tax evasion.