The House of Lords Act is given Royal Assent, restricting membership of the British House of Lords by virtue of a hereditary peerage.

The House of Lords Act 1999 (c. 34) is an Act of the Parliament of the United Kingdom that was given Royal Assent on 11 November 1999. The Act reformed the House of Lords, one of the chambers of Parliament. For centuries, the House of Lords had included several hundred members who inherited their seats (hereditary peers); the Act removed such a right. However, as part of a compromise, the Act did permit ninety-two hereditary peers to remain in the House on an interim basis. Another ten were created life peers to enable them to remain in the House.The Act decreased the membership of the House from 1,330 in October 1999 to 669 in March 2000. As another result of the Act, the majority of the Lords were now life peers, whose numbers had been gradually increasing since the Life Peerages Act 1958. As of November 2019, there were 793 members of the House of Lords, of whom 26 were senior Church of England bishops, whose representation in the House is governed by the Bishoprics Act 1878.