One common synonym for the Internal Revenue Service (IRS) is the tax collector. Another synonym is simply the tax agency. The taxman is sometimes used, particularly in more informal contexts. The Department of the Treasury is another term that is sometimes used in place of the IRS, since the agency falls under the jurisdiction of the Treasury. The Inland Revenue Service is a similar organization that exists in the United Kingdom, but it is not a synonym for the IRS in the United States. Ultimately, the IRS is the primary government agency responsible for collecting federal taxes and enforcing tax laws in the United States.