Understanding legislation

'Primary legislation' is the term used to describe the main laws passed by the legislative bodies of the UK e.g. Acts of the UK Parliament, Scottish Parliament, Welsh Parliament and Northern Ireland Assembly. It also includes Acts passed by historical parliaments, other primary legislation for Northern Ireland and Church of England Measures (legislation for the established church in England passed by the General Synod of the Church of England).

These types of legislation are sometimes referred to as 'statutes' and the term 'the statute book' refers to the whole of the statute law currently in force.

Certain legislative instruments made by the Crown and the Privy Council under the royal prerogative (called 'Prerogative Orders') are also referred to as Primary Legislation. Prerogative Orders are called either 'Orders in Council' (when made by the King on the advice of the Privy Council) or 'Orders of Council' (when made by the Lords of the Privy Council without any approval by the King). Note that such orders may also be made under powers in Statutory Instruments rather than under the prerogative (for example, the Orders in Council containing legislation for Northern Ireland).

'Secondary legislation' (also called 'subordinate legislation') is delegated legislation made by a person or body under authority contained in primary legislation. Typically, powers to make secondary legislation may be conferred on ministers, on the Crown, or on public bodies. For example, the Office of Communications (OFCOM) is given such powers by the Communications Act 2003.

The main types of secondary legislation are Statutory Instruments, Statutory Rules and Orders, Church Instruments.

There are three main types of UK Statutory Instrument: 'Orders', 'Regulations', 'Rules'. However, there is no limit imposed on the descriptions that may be given to Statutory Instruments. Other examples include 'Scheme', 'Direction' and 'Declaration'. Different types of instruments serve different functions, but they all have the same legislative force. Prior to 1948, when the Statutory Instruments Act 1946 came into force, the equivalent instruments were known as 'Statutory Rules and Orders'.

Church instruments are made by the Archbishops of Canterbury and York under authority contained in Church Measures. They are sometimes also referred to in annotations to the revised legislation as 'Archbishops Instruments', and are used almost exclusively for the purpose of bringing Church Measures into force.

Scottish Statutory Instruments are instruments made since 1999 under authority contained in Acts of the Scottish Parliament. As in the case of UK Statutory Instruments, there are three main types of Scottish Statutory Instrument ('Orders', 'Regulations' and 'Rules'). In addition, there are in Scotland rules of court contained in Statutory Instruments called 'Acts of Sederunt' and 'Acts of Adjournal'. There may also be other descriptions of Scottish Statutory Instruments.

Welsh Statutory Instruments are Statutory Instruments relating specifically to Wales. They may be made under authority contained in Acts of the UK Parliament, Measures of the National Assembly for Wales or Acts of the National Assembly for Wales or Acts of Senedd Cymru. Welsh Statutory Instruments are published in both the English and Welsh languages.

Statutory Rules of Northern Ireland are the equivalent of Statutory Instruments for Northern Ireland. They may be made under authority contained in Acts of the Northern Ireland Assembly. They may also be made under authority contained in Acts of the UK Parliament or in the Orders in Council containing the primary legislation for Northern Ireland during periods of direct rule by the UK government (and which continue to be used for matters that have not been devolved to the Assembly). Despite the name, Statutory Rules occur in the same three main types as Statutory Instruments ('Orders', 'Regulations' and 'Rules'). There may also be other descriptions of Statutory Rules.

Bye-laws

This is legislation delegated to bodies such as local authorities, operators of transport systems or public utilities. The application of bye-laws is usually limited to a particular local area or the operations of a specific public body. Legislation.gov.uk does not publish bye-laws.

Case Law

Case law is the set of rulings from court judgements that set precedents for how the law has been interpreted and applied in certain cases. Case law is not held on legislation.gov.uk. Some case law can be found at Find caselaw.

Citation and numbering

Primary legislation (e.g. Acts) are numbered chronologically within the year in which they are enacted. The numbering re-starts each year. For UK Public General Acts (UKPGA) the number is referred to as a 'Chapter'. Acts are therefore, usually cited by their type, year and chapter number e.g. The Data Protection Act 2018 is cited as '2018 c.12'. Acts of the Assembly of Northern Ireland also use chapter numbers, but are numbered separately so are cited on this website as '2018 c.3 (N.I)'. Acts of the Scottish Parliament have their own numbering system that works in the same way. The number is referred to as 'ASP' (standing for Act of the Scottish Parliament) e.g. Wild Animals in Travelling Circuses (Scotland) Act 2018 is cited as '2018 asp.3'. Acts of the National Assembly for Wales are numbered using 'anaw' (Act of the National Assembly for Wales) as the prefix for the number. Acts of Senedd Cymru are numbered ‘asc’ (Act of Senedd Cyrmru) as the prefix for the number.

UK Statutory Instruments are numbered sequentially each year. Welsh Statutory Instruments and the Orders in Council made under the Northern Ireland Acts are included in the same numbering sequence as UK Statutory Instruments. They are distinguished within that sequence by a subsidiary number in brackets after the S.I. number (e.g. '(W. 22)', '(N.I. 15)', etc.). There are also UK Statutory Instruments relating exclusively to Scotland which are included in the UK numbering sequence and distinguished by a subsidiary number (e.g. '(S. 27)'). These are not to be confused with Scottish Statutory Instruments which have their own 'SSI' numbering sequence, as do Statutory Rules of Northern Ireland which have their own 'SR' numbering sequence separate from the UK 'SI' sequence.

Full details about how we cite legislation on legislation.gov.uk are in our Guide to Revised Legislation.

Parliaments and jurisdictions

UK Parliament

Most of the Acts passed by the UK Parliament are 'Public General Acts'. These are Acts that deal with matters of general public interest. A small number of Acts are 'Private Acts'. These are further sub-divided into 'Local Acts' (which relate to matters of local interest) and 'Personal Acts' (which relate to particular persons, and are nowadays very rare). These two classes of Acts are numbered differently to Public General Acts.

Public and General Acts passed by the UK Parliament provide laws for the whole of the UK (England, Wales, Scotland and Northern Ireland). Separately Scotland, Wales and Northern Ireland have powers to make legislation solely for their own jurisdiction.

You can find out more about the UK parliament and the UK legislative process at www.parliament.uk.

Scottish Parliament

The current Scottish Parliament was established in 1999 by the Scotland Act 1998 to debate issues and make laws for Scotland. The Scottish Parliament has power to make laws on a range of issues that are known as devolved matters. Some issues remain the responsibility of the UK Parliament alone. These are known as reserved matters. Further powers are transferred to the Scottish Parliament through the Scotland Act 2016 in areas such as taxation, welfare and elections. Your Scottish Parliament is a leaflet published by the Scottish Parliament that explains how the Scottish parliament makes laws.

Welsh Parliament

The Welsh Parliament is the democratically elected body that represents the interests of Wales and its people. The Welsh Parliament makes laws for Wales on specific subject areas. Outside these areas, different bodies (like local authorities or the UK government) make laws that apply to Wales.

Acts of Senedd Cymru (made from May 2020), as well as Acts of the National Assembly for Wales (made from 2011-2020) and Measures of the National Assembly for Wales (made from 2008 – 2011), are published in both the English and Welsh languages.

You can find out more about the Welsh Parliament and the legislative process in Wales at gov.wales and www.senedd.wales.

Northern Ireland Assembly

The Northern Ireland Assembly was established as a result of the Belfast Agreement of 10 April 1998.

The Agreement was subsequently given legal force through the Northern Ireland Act 1998. It led to the creation of a series of interrelated bodies, in particular the Northern Ireland Assembly, which, when it is functioning, has full legislative and executive authority for all matters that are the responsibility of the Northern Ireland Government Departments and are known as transferred matters. Excepted matters remain the responsibility of the Westminster Parliament. Reserved matters are also dealt with by Westminster unless it is decided by the Secretary of State that some of these should be devolved to the Assembly. Excepted and reserved matters are defined in the Schedules to the NI Act.

How Parliaments have changed and created different legislation types

UK

There are still many Acts in force that were enacted by the parliaments of the separate countries that co-existed in the British Isles before the United Kingdom of Great Britain and Ireland was formed in 1801. These are Acts that were enacted by:

Scotland

There are still Acts in force that were enacted by the Old Scottish Parliament from 1424 - 1707. These are referred to on this site as 'Acts of the Old Scottish Parliament' whereas acts passed by the current Scottish Parliament are referred to as 'Acts of the Scottish Parliament'.

The history of the Scottish Parliament is explained in detail on the History section of the Scottish Parliament website.

Wales

The Government of Wales Act 2006 set out devolved power to make primary legislation in relation to matters set out in the Act to the National Assembly for Wales sitting in Cardiff. Initially, this legislation took the form of 'Measures' (but see 'Acts of the National Assembly for Wales' below). The Assembly had earlier been established by the Government of Wales Act 1998 with powers to legislate by means of secondary legislation in the form of Statutory Instruments.

Following a referendum in March 2011, the National Assembly for Wales acquired the power, provided for in the Government of Wales Act 2006, to make 'Acts' in relation to subject areas set out in that Act. Unlike the earlier Measures, Acts of the National Assembly for Wales can be passed without first seeking the approval of the UK Government or Parliament. On the 6th of May 2020, Section 2 of the Senedd and Elections (Wales) Act 2020 (anaw 1) changed the name of the National Assembly for Wales to the Welsh Parliament.

Northern Ireland

As a result of the complex history of the political situation in Northern Ireland since 1921, there have been a number of changes in the way that primary legislation has been made. The types of primary legislation for Northern Ireland still extant are: Acts of the Parliament of Northern Ireland (1921 – 1972) Measures of the Northern Ireland Assembly (1974 only) Acts of the Northern Ireland Assembly (2000 – 2002 and 2007 to date) Orders in Council made under the Northern Ireland Acts (1972 to date) Although this last category of legislation takes the form of UK statutory instruments (which are secondary legislation), it constitutes, in effect, the primary legislation for Northern Ireland during periods of 'direct rule' by the UK government. Orders in Council continue to be used to legislate for Northern Ireland in relation to matters that have not been devolved to the Assembly. Visit the Northern Ireland Assembly website to find out more about the history of the Northern Ireland Assembly and how the assembly operates.

How legislation can extend and apply to different parts of the UK

The term 'Geographical Extent' is used to describe the geographical area within the UK to which a piece of legislation (or part/section of a piece of legislation) applies.

The term 'extent' when used in legislation refers to the jurisdiction(s) for which it is law. Thus, the extent may be the whole of the UK or one or more of the three jurisdictions within the UK: England and Wales; Scotland; and Northern Ireland. Note that England and Wales are not separate jurisdictions. The term 'extent' is currently used more loosely on legislation.gov.uk for searching purposes, to help users find legislation relevant to each of the four geographical parts of the UK. For this reason, it may denote a limited territorial application within a wider technical extent. For example, the extent of the legislation may be 'England and Wales' but it only applies to Wales. In due course, changes will be made to the way in which 'extent' information is presented on legislation.gov.uk so that information about extent and limited territorial application within a wider extent will be displayed separately.

Currently, each 'extent' is represented by one of, or a combination of, England (E), Wales (W), Scotland (S) and Northern Ireland (NI). Thus, a UK extent is E+W+S+NI and a GB extent is E+W+S. This information can be displayed within revised legislation when it is being viewed by selecting 'show geographical extent' in the left-hand column.

Every version of every provision (e.g. section of an act) and every higher level of division within a piece of legislation (whole legislation or part level) is assigned its own extent. In the case of higher levels of divisions (at whole legislation level or part level) the extent will be set wide enough to include the extent of all the provisions (e.g. sections) within it.

In some limited cases there may be multiple versions created to represent differing geographical extents. Two or more versions of a provision (or other level of division of legislation) are created where a substitution of text (or of the whole provision etc.) affects only part of the original geographical extent of the provision. Such versions have the same start date and continue to run alongside one another.

For instance, if there is a substitution of text in a provision that extends to the whole of the UK, but the substitution affects Wales only, two versions result: one for the provision in its unamended state to cover England, Scotland and Northern Ireland, and one for the provision as amended to cover Wales.

Associated documents published with legislation

A variety of documents can be published alongside legislation. A selection of the most common documents are explained below:

Explanatory Note(s)

Explanatory Notes are documents that typically accompany primary legislation (e.g. an Act or Measure). The text is created by the government department responsible for the subject matter of the Act (or Measure) to explain what the Act sets out to achieve and to make the Act accessible to readers who are not legally qualified. Explanatory Notes were introduced in 1999 and accompany all Public Acts except Appropriation, Consolidated Fund, Finance and Consolidation Acts.

Text called an Explanatory Note also appears following the legislative text of Statutory Instruments, Scottish Statutory Instruments or Statutory Rules of Northern Ireland. For Welsh Statutory Instruments the Explanatory Note precedes the body of the Instrument in print format but follows the legislative text in html format. The Explanatory Note is intended to give a concise and clear statement of the substance of the instrument. The instrument itself may also be accompanied by a separate explanatory document. For secondary legislation, such as Statutory Instruments, these are called Explanatory Memorandum or Executive Note/Policy Note for Scottish Statutory Instruments.

Explanatory Memorandum

An Explanatory Memorandum (EM) sets out a brief statement of the purpose of a Statutory Instrument or Statutory Rules of Northern Ireland and provides information about its policy objective and policy implications. It aims to make the Statutory Instruments or Rules accessible to readers who are not legally qualified. EMs accompany any Statutory Instrument or Draft Statutory Instrument laid before Parliament from June 2004 onwards and any Statutory Rule laid before the Northern Ireland Assembly (or UK Parliament during the suspension of the Northern Ireland Assembly) since June 2004.

Policy Note for Scottish Statutory Instruments

A Policy Note sets out a brief statement of the purpose of a Scottish Statutory Instrument and provides information about its policy objective and policy implications. It aims to make the Scottish Statutory Instrument accessible to readers who are not legally qualified. Policy Notes accompany any Scottish Statutory Instrument or Draft Scottish Statutory Instrument laid before the Scottish Parliament from July 2005 onwards. Note that they were originally called Executive Note but have been called Policy Note from July 2012.

Impact Assessment

Impact Assessments generally accompany all UK Government interventions of a regulatory nature that affect the private sector, civil society organisations and public services. They apply regardless of whether the regulation originates from a domestic or international source and can accompany primary (Acts etc) and secondary legislation (Statutory Instruments). An Impact Assessment allows those with an interest in the policy area to understand: why the government is proposing to intervene; the main options the government is considering, and which one is preferred; how and to what extent new policies may impact on them; and, the estimated costs and benefits of proposed measures.

Corrections

If a piece of legislation contains substantive errors, a new piece of legislation will be enacted to correct those errors. If the errors are minor and do not change the meaning of the legislation, but ought to be corrected to avoid misleading readers – for example a wrong cross reference - a correction slip will be produced and published alongside the legislation. The correction will be made on the website copy, but the original print PDF will not be changed. We do apply the corrections to the annual print bound volumes of legislation that are produced.

How legislation comes into force and is amended

An Act of Parliament creates a new law or changes an existing law. An Act is a Bill that has been approved by both the House of Commons and the House of Lords and been given Royal Assent by the Monarch. Taken together, Acts of Parliament make up what is known as Statute Law in the UK.

An Act may come into force immediately, on a specific future date, or in stages. You can find out when an Act is due to come into force by looking at a section of the Act itself, headed 'Commencement' – this is among the very last sections of an Act.

Sometimes a specific date is not given and the timing is left to the discretion of the Secretary of State for the relevant government department. An act can therefore come into force by way of a Statutory Instrument called a 'Commencement Order' or 'Commencement Regulation'.

Future changes to the law happen through the passing of another Act or delegated legislation (e.g. secondary legislation such as Statutory Instruments). The change, or amendment, can itself be subject to coming into force immediately, on a specific future date, or in stages. An Act can also be repealed so that its provisions are no longer in force.

On legislation.gov.uk we provide details about complex in force scenarios by way of I-note annotations on our revised versions. Please note that our enacted versions do not provide any information about in force/commencement.

What legislation is held on legislation.gov.uk

Legislation.gov.uk carries most (but not all) types of legislation and their accompanying explanatory documents. For further details of how complete our data set is for each type, click on a legislation type from the Browse Legislation page and see the colour coded bar for each year. It also contains legislation originating from the European Union, including corrigenda (correction slips for EU legislation) and EU Directives published up to EU exit. See EU Legislation and UK Law for more information.

Revised legislation on legislation.gov.uk

Most types of primary legislation (e.g. Acts, Measures, N.I. Orders in Council) are held in 'revised' form, as well as selected secondary legislation, and legislation originating from the EU:

Revised versions of some secondary legislation (e.g. Statutory Instruments) are also held on legislation.gov.uk. More secondary legislation is being revised as part of our work and will be published as it becomes available.

By 'revised' we mean that amendments made by subsequent legislation are incorporated into the text. Most secondary legislation is not currently revised and is held only in the form in which they were originally made.

The originating text of the revised primary content was derived mainly from the publication Statutes in Force (SIF), a 'loose-leaf' style official edition of the revised statute book arranged according to subject matter. SIF was regularly updated with the effects of new legislation made until 1 February 1991. The date of this final revision became the 'base date' from which the revised content has been taken forward on the web. SIF did not generally include certain categories of legislation, such as Statute Law Revision Acts, Statute Law (Repeals) Acts and Acts extending only to Northern Ireland. (For further details, see the Guide to Revised Legislation on legislation.gov.uk at page 6). The other main source of revised legislation held on legislation.gov.uk is The Northern Ireland Statutes Revised, the official revised version of the primary legislation of Northern Ireland. The content of the numbered volumes and their supplements covering the period from 1921 onwards has been incorporated into legislation.gov.uk as it stood at 31 December 2005.

See EU Legislation and UK Law for more information on revised legislation originating from the EU.

Our editorial practice and timescales

Revising legislation on legislation.gov.uk involves amending the text of the legislation where appropriate and adding annotations containing information about effects on legislation, or other editorial information.

We aim to present the revised text of legislation clearly and accurately without gloss or comment, giving authority for changes to the text, and recording any other effects that make some difference to the meaning, scope or application of the legislation. But otherwise, we aim to let the legislation speak for itself precisely as the legislature has framed it.

When we receive a new piece of legislation, a newly enacted Act for example, we analyse it to identify all its impacts on other legislation. These are mostly amendments to the text of the other legislation. But there are also many effects that do not change the text, such as when the other legislation is said to be 'applied' or 'modified'. We also note other information about new primary legislation, such as when it comes into force and its geographical extent or territorial application. We use this information when setting up the timeline and extent facilities for the legislation and its provisions on legislation.gov.uk.

An 'as enacted' version of the legislation is published on legislation.gov.uk shortly after it is enacted. Once we have entered all of the impacts on other legislation, and inserted any annotations needed at this stage about commencement or extent, we publish a 'Latest Available (Revised)' version.

Once we have analysed the legislation, we tabulate the extracted information about its effects on other legislation and add it to 'Changes to Legislation'. We aim to do this as soon as possible, but it can take up to six weeks if the document is large or if there is a high volume of new legislation. This is the case with legislation originating from the European Union, where over 100,000 amendments came into force at 11.00 p.m. on 31 December 2020. It will take the legislation.gov.uk editorial team some time to implement these amendments – see Revising legislation originating from the EU for more information.

If the primary legislation on legislation.gov.uk has any unapplied effects, we flag them in the 'Changes to Legislation' banner on the website. Clicking on the banner reveals the outstanding changes.

We aim to incorporate new amendments into the text of the legislation within three months of those amendments coming into force.

Full details about how we edit legislation and apply changes can be read in our Guide to Revised Legislation.

Legislation originating from the EU

Schedule 5 to the European Union (Withdrawal) Act 2018 (c. 16), as amended by the European Union (Withdrawal Agreement) Act 2020 Sch.5 para. 48, requires that we make arrangements for the publication of EU Regulations, EU Decisions, and EU tertiary legislation published on EUR-Lex up to 11.00 p.m. on 31 December 2020.

It also requires four international agreements to be published – the Treaty on European Union, the Treaty on the Functioning of the European Union, the Euratom Treaty, and the EEA agreement. These are now published on legislation.gov.uk.

The European Union (Withdrawal) Act 2018 also gives the power to publish other legislation documents that may be useful, and legislation.gov.uk therefore also includes corrigenda (correction slips for EU legislation) and EU Directives as published on EUR-Lex. We captured and published these up to 11.00 p.m. on 31 December 2020.

The EU Exit Web Archive contains a wider selection of documents, including Treaties, legislative documents, the Official Journal of the EU, case law and other supporting materials, and judgements of the European Court of Justice in English, French and German. We captured these from EUR-Lex up to 11.00 p.m. on 31 December 2020.

All content is available under the Open Government Licence v3.0 except where otherwise stated. This site additionally contains content derived from EUR-Lex, reused under the terms of the Commission Decision 2011/833/EU on the reuse of documents from the EU institutions. For more information see the EUR-Lex public statement on re-use.

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