Internal Revenue Service (IRS)

The IRS is responsible for collecting taxes and administering the Internal Revenue Code, which contains the great majority of the federal tax laws in the U.S. Its duties also include assisting the Treasury Department in setting tax policy through regulations, which are designed to provide guidance to taxpayers in complying with the tax laws. IRS is also responsible for providing assistance to taxpayers and pursuing and resolving cases of erroneous or fraudulent tax filings.