This chapter examines ‘primary legislation’, in the form of UK Acts of Parliament, and how they are made. The discussions cover who or what is the ‘legislature’ in the British constitution; the roles of different institutions in policymaking; drafting bills by Parliamentary Counsel; pre-legislative scrutiny of some ‘draft bills’ before the start the formal legislative process in Parliament ; the parliamentary year; parliamentary stages of a bill—first reading, second reading, committee stage, report stage, and third reading; bills of constitutional importance; the constitutional framework for bringing legislation into force; how government and Parliament carries out post-legislative scrutiny of some Acts of Parliament to review how they are operating in practice; and legislative functions in the British system of devolution.