You can't simply shut down the IRS like you would some other government agency. Why not? Because they are partly a private industry. IRS taxes are voluntary. The basic legality for the IRS tax is found in the Contract Clause in the US Constitution. The pertinent part is, "No State shall enter into any ... Law impairing the Obligation of Contracts... ." The point is, that for the IRS to have authority, somebody has to have signed a document or form that indicates a relationship with the IRS. All such signing is voluntary, even if it is done under threat or duress. For most people who are young, maybe on their first job, IRS Form W-4 is where they come under the IRS. For those going to court against the IRS, signing up with an attorney makes a person a ward of the court, and liable for whatever decisions the court makes.