Coming into force

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.

General requirements
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.

Treaties
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.

Acts
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 Moreover, an Act may be repealed having never come into force.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.

Typically, the process by which a bill becomes an Act includes signature or some other token of assent by the head of state and publication in an official gazette. In some systems, the head of state or some other official is required to definitely signify his approval, as for example in the granting of royal assent in the Commonwealth realms. In others, a bill automatically becomes an Act unless vetoed, as for example in the United States. But these steps do not, in themselves, make an act legally binding on the population. An act is typically brought into force in one of three ways:
 * By means of an explicit commencement date (and sometimes time of day) written into the act itself. It is possible for different sections of an act to come into force at different dates or times.
 * As a result of a commencement order. Usually, an Act or part of an Act may only be brought into force by a commencement order if explicit provision is made. Commencement orders are typically issued by the executive branch of government, though they may also require legislative approval, or at least that the legislature be informed. As with explicit commencement dates, different parts of an act may be brought into force by different commencement orders at different times.
 * Automatically. An Act that does not include explicit commencement dates or provision for commencement orders, or that has dates or provides for commencement orders for only some of its contents, will typically be interpreted as having come into effect at a certain time relative to its enactment. This time is usually specified by an interpretive statute, or, in the absence of such a statute, a legal rule. For example, in the United Kingdom, until late in the 18th century a legal rule interpreted statutes as coming into effect at the start of the legislative session in which they were passed, but Acts of Parliament (Commencement) Act 1793 stipulated that future laws without explicit commencement provisions would come into effect on the day on which they received royal assent. A similar example is provided by New Zealand, where an Act without commencement provisions comes into force on the day after the day on which it received royal assent.
 * It is possible for an Act to come into effect through any combination of these three methods.

United Kingdom
Section 4 of the Interpretation Act 1978 provides:

"An Act or provision of an Act comes into force—
 * (a) where provision is made for it to come into force on a particular day, at the beginning of that day;
 * (b) where no provision is made for its coming into force, at the beginning of the day on which the Act receives the Royal Assent."

This replaces the corresponding provision in the Acts of Parliament (Commencement) Act 1793.

Schedule 1 of that Act contains the following definition:

""Commencement", in relation to an Act or enactment, means the time when the Act or enactment comes into force."

Northern Ireland
Sections 14(1) and (2) of the Interpretation Act (Northern Ireland) 1954 read:

"(1) Every enactment which is not expressed to come into force or operation on a particular day shall come into operation immediately on the expiration of the day before the date of the passing thereof, or, where the enactment is a statutory instrument, of the making thereof. (2) Where an enactment is expressed to come into force or operation on a particular day (whether such day is before or after the date of the passing of such enactment, or where the enactment is a statutory instrument, of the making thereof, and whether such day is named in the enactment or is to be appointed or fixed or ascertained in any other manner) the enactment shall be construed as coming into force immediately on the expiration of the day before that particular day."

In an enactment the expression "commencement", when used with reference to any statutory provision, means the time at which that provision comes into operation.

Scotland
Sections 2 and 3 of the Interpretation and Legislative Reform (Scotland) Act 2010, which applies to Acts of the Scottish Parliament and Scottish Statutory Instruments, provide-

"2 Commencement of Acts of the Scottish Parliament (1) Subsection (2) applies where no provision is made for the coming into force of an Act of the Scottish Parliament. (2) The Act comes into force at the beginning of the day after the day on which the Bill for the Act receives Royal Assent.

3 Commencement of Acts of the Scottish Parliament and Scottish instruments: time (1) Subsection (2) applies where an Act of the Scottish Parliament or a Scottish instrument provides for the Act or instrument to come into force on a particular day. (2) The Act or instrument comes into force at the beginning of the day."

This replaces the temporary provision made by the Scotland Act 1998 (Transitory and Transitional Provisions) (Publication and Interpretation etc. of Acts of the Scottish Parliament) Order 1999.

History
According to the legal sociology of Max Weber, "revelation [to a magician or priest] of law in these forms was the original revolutionary element opposing the stability of tradition and is the mother of all legal 'enactment'".