People who work to influence government policies and actions by advocating for their own or their client's interests are known as lobbyists. They work in government affairs or in public relations departments for trade associations, professional societies, labor unions, corporations, and a wide variety of special interest and public interest groups. Some are registered as lobbyists on Capitol Hill. Others, who represent foreign industry or governments, are registered with the Justice Department as foreign agents Still others are part of the executive branch of the federal government and act as liaisons between that office and Congress.
The Justice Department requires agents representing foreign countries and organizations to file forms in their Foreign Agents Registration Unit: (202) 514-1216. These files are open for public inspection at the Justice Department.
Lobbyists also register with the Clerk of the House of Representatives and Secretary of the Senate, indicating the party or individuals in whose interest they work, the length of employment, amount of reimbursement received by the lobbyist, and what expenses are covered by this reimbursement. Furthermore, lobbyists must file quarterly financial reports stating the name and address of each individual who has made a contribution of $500 or more, and the total contributions made during the calendar year.
For further information, check these publications: