Coming into force or entry into force (also called commencement) refers to the process by which legislation, regulations, treaties and other legal instruments come to have legal force and effect. The term is closely related to the date of this transition.
To come into force, a treaty or Act first needs to receive the required number of votes or ratifications. Sometimes, as with most treaties, this number will be stipulated as part of the treaty itself. Other times, as is usual with laws or regulations, it will be spelt out in a superior law, such as a written constitution or the standing orders of the deliberative assembly in which it originated.
Coming into force generally includes publication in an official gazette so that people know the law or treaty exists, which generally releases it into the public domain.
After their adoption, treaties as well as their amendments may have to follow the official legal procedures of the United Nations, as applied by the Office of Legal Affairs, including signature, ratification, and entry into force.
The process of enactment, by which a bill becomes an Act, is separate from commencement. Even if a bill passes through all necessary stages to become an Act, it may not automatically come into force. Moreover, an Act may be repealed having never come into force.
A country's law could determine that on being passed by lawmakers a bill becomes an act without further ado. However, more usually, the process whereby a bill becomes an Act is well prescribed in general constitutional or administrative legislation. This process varies from country to country, and from political system to political system.