Overview

An Act of Parliament is a formal written law enacted by a legislative body. In many systems it is the highest form of domestic law and is often described as primary legislation. The term covers statutes made by an elected or representative parliament and is commonly distinguished from delegated or secondary legislation. An Act becomes binding on citizens and public bodies once it has completed the required enactment steps in a given jurisdiction and entered into force as law.

Typical structure and parts

Most Acts share a consistent internal structure that helps users find and apply the law. Common elements include:

  • Title and long title — a short name and a descriptive long title describing the purpose.
  • Enacting clause — a formal statement that the legislature has enacted the provisions.
  • Sections and subsections — the main numbered provisions that create rights, duties or powers.
  • Schedules — detailed material, forms or transitional arrangements placed at the end.
  • Commencement, citations and repeals — provisions that state when the Act takes effect and how it may be cited or amended.

How an Act becomes law

The legislative process varies by country but generally involves introduction of a bill, debates and committee scrutiny, staged readings, and a vote in the legislature. After passage by the parliamentary houses required by a constitution, the bill usually receives final formal approval (for example, Royal Assent in some constitutional monarchies or presidential assent in republics) before it becomes an Act. Many Acts specify different commencement dates or delegate power to a minister to bring provisions into force.

Types and examples

Acts are often classified by purpose: public general Acts apply broadly across the jurisdiction; private or local Acts affect particular individuals, corporations or areas; amending Acts change existing statutes; consolidation Acts reorganize multiple laws without changing substance; enabling Acts grant power for subordinate rules. Because Acts are primary law, they set the framework within which subordinate instruments operate.

The idea of statutes enacted by a representative assembly dates back centuries and has evolved differently across systems. In countries influenced by the Westminster model, Acts reflect the doctrine that an elected parliament is the principal law-making authority. Acts are central to modern governance: they allocate public resources, define criminal offences, regulate markets and protect rights. Courts interpret Acts when disputes arise and may read them alongside constitutional provisions and international obligations.

For further reading on related concepts, see general resources on legislation, the nature of law, and the role of parliament in making statutes.