Interpretation Act 1978

General provisions as to enactment and operation U.K.

1 Words of enactment. U.K.

Every section of an Act takes effect as a substantive enactment without introductory words.

2 Amendment or repeal in same Session. U.K.

Any Act may be amended or repealed in the Session of Parliament in which it is passed.

3 Judicial notice. U.K.

Every Act is a public Act to be judicially noticed as such, unless the contrary is expressly provided by the Act.

4 Time of commencement. U.K.

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.

Interpretation and construction U.K.

5 Definitions. U.K.

In any Act, unless the contrary intention appears, words and expressions listed in Schedule 1 to this Act are to be construed according to that Schedule.

6 Gender and number. U.K.

In any Act, unless the contrary intention appears,—

(a) words importing the masculine gender include the feminine;

(b) words importing the feminine gender include the masculine;

(c) words in the singular include the plural and words in the plural include the singular.

Modifications etc. (not altering text)

C1 S. 6(a) excluded (E.W.) by Sexual Offences Act 1985 (c. 44, SIF 39:5), ss. 4(3), 5(5)

C2 S. 6(b) excluded (E.W.) by Sexual Offences Act 1985 (c. 44, SIF 39:5), ss. 4(3), 5(5)

C3 S. 6(b) excluded (E.W.S.) by Employment Act 1989 (c. 38, SIF 43:1), ss. 5(4)(7), 29(6), Sch. 9 para. 4(1)

7 References to service by post. U.K.

Where an Act authorises or requires any document to be served by post (whether the expression “serve” or the expression “give” or “send” or any other expression is used) then, unless the contrary intention appears, the service is deemed to be effected by properly addressing, pre-paying and posting a letter containing the document and, unless the contrary is proved, to have been effected at the time at which the letter would be delivered in the ordinary course of post.

Modifications etc. (not altering text)

C4 S. 7 modified (E.W.) (1.7.1995) by 1994 c. 36, s. 17(2)(3) (with s. 20); S.I. 1995/1317, art. 2

C5 S. 7 excluded by Insurance Companies Act 1982 (c. 50, SIF 67), s. 77(4)

S. 7 excluded (E.W.) by Enduring Powers of Attorney Act 1985 (c. 29, SIF 1), s. 4(3), Sch. 1 Pt. IV para. 8(2)

S. 7 excluded by Public Order Act 1986 (c. 64, SIF 39:2), s. 11(5)

S. 7 excluded (20.6.2003) by The Enterprise Act 2002 (Merger Prenotification) Regulations 2003 (S.I. 2003/1369), regs. 5, 11, 12, 13(5)

S. 7 excluded (E.W.) (1.7.2005 for certain purposes and 1.8.2005 otherwise) by Serious Organised Crime Act 2005 (c. 15), ss. 133(6), 178; S.I. 2005/1521, arts. 3(1)(p), 4(1)

S. 7 excluded (E.W.) (1.10.2007) by The Mental Capacity Act 2005 (c. 9), ss. 66(3), 68(1), Sch. 4 para. 12 (with ss. 27-29, 62); S.I. 2007/1897, art. 2(1)(d)

8 References to distance. U.K.

In the measurement of any distance for the purposes of an Act, that distance shall, unless the contrary intention appears, be measured in a straight line on a horizontal plane.

9 References to time of day. U.K.

Subject to section 3 of the M1 Summer Time Act 1972 (construction of references to points of time during the period of summer time), whenever an expression of time occurs in an Act, the time referred to shall, unless it is otherwise specifically stated, be held to be Greenwich mean time.

Marginal Citations

M1 1972 c. 6.

10 References to the Sovereign. U.K.

In any Act a reference to the Sovereign reigning at the time of the passing of the Act is to be construed, unless the contrary intention appears, as a reference to the Sovereign for the time being.

11 Construction of subordinate legislation. U.K.

Where an Act confers power to make subordinate legislation, expressions used in that legislation have, unless the contrary intention appears, the meaning which they bear in the Act.

Modifications etc. (not altering text)

C6 S. 11 applied (1.1.1995) by S.I. 1994/3144, reg. 1(6)

C7 S. 11 excluded (E.W.) (1.9.1997) by S.I. 1997/1972, reg. 2(3)

C8 S. 11 applied (30.10.2005) by The Medicines (Traditional Herbal Medicinal Products for Human Use) Regulations 2005 (S.I. 2005/2750), regs. 1, 2(3) (with transitional provisions in reg. 12, Sch. 6)

C9 S. 11 excluded (S.) (1.8.2007) by The Education (Fees and Awards) (Scotland) Regulations 2007 (S.S.I. 2007/152), reg. 2(2)

C10 S. 11 excluded (W.) (31.8.2007) by The Education (Fees and Awards) (Wales) Regulations 2007 (S.I. 2007/2310), reg. 2(2)

C11 S. 11 excluded (S.) (1.8.2012) by The Education (Fees) (Scotland) Regulations 2011 (S.S.I. 2011/389), regs. 1(1), 2(2)

Statutory powers and duties U.K.

12 Continuity of powers and duties. U.K.

(1) Where an Act confers a power or imposes a duty it is implied, unless the contrary intention appears, that the power may be exercised, or the duty is to be performed, from time to time as occasion requires.

(2) Where an Act confers a power or imposes a duty on the holder of an office as such, it is implied, unless the contrary intention appears, that the power may be exercised, or the duty is to be performed, by the holder for the time being of the office.

13 Anticipatory exercise of powers. U.K.

Where an Act which (or any provision of which) does not come into force immediately on its passing confers power to make subordinate legislation, or to make appointments, give notices, prescribe forms or do any other thing for the purposes of the Act, then, unless the contrary intention appears, the power may be exercised, and any instrument made thereunder may be made so as to come into force, at any time after the passing of the Act so far as may be necessary or expedient for the purpose—

(a) of bringing the Act or any provision of the Act into force; or

(b) of giving full effect to the Act or any such provision at or after the time when it comes into force.

14 Implied power to amend. U.K.

Where an Act confers power to make—

(a) rules, regulations or byelaws; or

(b) Orders in Council, orders or other subordinate legislation to be made by statutory instrument,

it implies, unless the contrary intention appears, a power, exercisable in the same manner and subject to the same conditions or limitations, to revoke, amend or re-enact any instrument made under the power.

Valid from 25/04/2013

[F1 14A Power to include sunset and review provisions in subordinate legislation U.K.

(1) This section applies where an Act confers a power or a duty on a person to make subordinate legislation except to the extent that—

(a) the power or duty is exercisable by the Scottish Ministers, or

(b) the power or duty is exercisable by any other person within devolved competence (within the meaning of the Scotland Act 1998).

(2) The subordinate legislation may include—

(a) provision requiring the person to review the effectiveness of the legislation within a specified period or at the end of a specified period;

(b) provision for the legislation to cease to have effect at the end of a specified day or a specified period;

(c) if the power or duty is being exercised to amend other subordinate legislation, provision of the kind mentioned in paragraph (a) or (b) in relation to that other legislation.

(3) The provision that may be made by virtue of subsection (2)(a) includes provision requiring the person to consider whether the objectives which it was the purpose of the legislation to achieve remain appropriate and, if so, whether they could be achieved in another way.

(4) Subordinate legislation including provision of a kind mentioned in subsection (2) may make such provision generally or only in relation to specified provisions of the legislation or specified cases or circumstances.

(5) Subordinate legislation including provision of a kind mentioned in subsection (2) may make transitional, consequential, incidental or supplementary provision or savings in connection with such provision.

(6) In this section, “specified” means specified in the subordinate legislation.]

Textual Amendments

F1 S. 14A inserted (25.4.2013) by Enterprise and Regulatory Reform Act 2013 (c. 24), ss. 59(2), 103(1)(e)

Repealing enactments U.K.

15 Repeal of repeal. U.K.

Where an Act repeals a repealing enactment, the repeal does not revive any enactment previously repealed unless words are added reviving it.

16 General savings. U.K.

(1) Without prejudice to section 15, where an Act repeals an enactment, the repeal does not, unless the contrary intention appears,—

(a) revive anything not in force or existing at the time at which the repeal takes effect;

(b) affect the previous operation of the enactment repealed or anything duly done or suffered under that enactment;

(c) affect any right, privilege, obligation or liability acquired, accrued or incurred under that enactment;

(d) affect any penalty, forfeiture or punishment incurred in respect of any offence committed against that enactment;

(e) affect any investigation, legal proceeding or remedy in respect of any such right, privilege, obligation, liability, penalty, forfeiture or punishment;

and any such investigation, legal proceeding or remedy may be instituted, continued or enforced, and any such penalty, forfeiture or punishment may be imposed, as if the repealing Act had not been passed.

(2) This section applies to the expiry of a temporary enactment as if it were repealed by an Act.

Modifications etc. (not altering text)

C12 S. 16 excluded (E.W.) by Mineral Workings Act 1985 (c. 12, SIF 86), ss. 3(3), 6(2)

C13 S. 16 excluded by Agricultural Holdings Act 1986 (c. 5, SIF 2:3), s. 99, Sch. 13 paras. 3, 8

C14 S. 16 excluded (S.) (25.9.1991) by Agricultural Holdings (Scotland) Act 1991 (c. 55, SIF 2:3), ss. 87, 89(2), Sch. 12 para. 5

17 Repeal and re-enactment. U.K.

(1) Where an Act repeals a previous enactment and substitutes provisions for the enactment repealed, the repealed enactment remains in force until the substituted provisions come into force.

(2) Where an Act repeals and re-enacts, with or without modification, a previous enactment then, unless the contrary intention appears,—

(a) any reference in any other enactment to the enactment so repealed shall be construed as a reference to the provision re-enacted;

(b) in so far as any subordinate legislation made or other thing done under the enactment so repealed, or having effect as if so made or done, could have been made or done under the provision re-enacted, it shall have effect as if made or done under that provision.

Modifications etc. (not altering text)

C15 S. 17(2)(a) excluded by Insurance Companies Act 1982 (c. 50, SIF 67), s. 99(1), Sch. 4 para. 17

Miscellaneous U.K.

18 Duplicated offences. U.K.

Where an act or omission constitutes an offence under two or more Acts, or both under an Act and at common law, the offender shall, unless the contrary intention appears, be liable to be prosecuted and punished under either or any of those Acts or at common law, but shall not be liable to be punished more than once for the same offence.

19 Citation of other Acts. U.K.

(1) Where an Act cites another Act by year, statute, session or chapter, or a section or other portion of another Act by number or letter, the reference shall, unless the contrary intention appears, be read as referring—

(a) in the case of Acts included in any revised edition of the statutes printed by authority, to that edition;

(b) in the case of Acts not so included but included in the edition prepared under the direction of the Record Commission, to that edition;

(c) in any other case, to the Acts printed by the Queen’s Printer, or under the superintendence or authority of Her Majesty’s Stationery Office.

(2) An Act may continue to be cited by the short title authorised by any enactment notwithstanding the repeal of that enactment.

20 References to other enactments. U.K.

(1) Where an Act describes or cites a portion of an enactment by referring to words, sections or other parts from or to which (or from and to which) the portion extends, the portion described or cited includes the words, sections or other parts referred to unless the contrary intention appears.

(2) Where an Act refers to an enactment, the reference, unless the contrary intention appears, is a reference to that enactment as amended, and includes a reference thereto as extended or applied, by or under any other enactment, including any other provision of that Act.

Modifications etc. (not altering text)

C16 S. 20(2) applied (5.6.2003) by The Immigration (Jersey) Order 1993 (S.I. 1993/1797), art. 4(1) (as amended by The Immigration and Asylum Act 1999 (Jersey) Order 2003 (S.I. 2003/1252), art. 3(a))

C17 S. 20(2) excluded (8.7.2003) by National Minimum Wage (Enforcement Notices) Act 2003 (c. 8), s. 2(2)(4)

Valid from 08/01/2007

[F2 20A References to Community instruments U.K.

Where an Act passed after the commencement of this section refers to a Community instrument that has been amended, extended or applied by another such instrument, the reference, unless the contrary intention appears, is a reference to that instrument as so amended, extended or applied.]

Textual Amendments

F2 S. 20A inserted (8.1.2007) by Legislative and Regulatory Reform Act 2006 (c. 51), ss. 25(1), 33

Supplementary U.K.

21 Interpretation etc. U.K.

(1) In this Act “Act” includes a local and personal or private Act; and “subordinate legislation” means Orders in Council, orders, rules, regulations, schemes, warrants, byelaws and other instruments made or to be made under any Act.

(2) This Act binds the Crown.

22 Application to Acts and Measures. U.K.

(1) This Act applies to itself, to any Act passed after the commencement of this Act and, to the extent specified in Part I of Schedule 2, to Acts passed before the commencement of this Act.

(2) In any of the foregoing provisions of this Act a reference to an Act is a reference to an Act to which that provision applies; but this does not affect the generality of references to enactments or of the references in section 19(1) to other Acts.

(3) This Act applies to Measures of the General Synod of the Church of England (and, so far as it relates to Acts passed before the commencement of this Act, to Measures of the Church Assembly passed after 28th May 1925) as it applies to Acts.

23 Application to other instruments. U.K.

(1) The provisions of this Act, except sections 1 to 3 and 4(b), apply, so far as applicable and unless the contrary intention appears, to subordinate legislation made after the commencement of this Act and, to the extent specified in Part II of Schedule 2, to subordinate legislation made before the commencement of this Act, as they apply to Acts.

(2) In the application of this Act to Acts passed or subordinate legislation made after the commencement of this Act, all references to an enactment include an enactment comprised in subordinate legislation whenever made, and references to the passing or repeal of an enactment are to be construed accordingly.

(3) Sections 9 and 19(1) also apply to deeds and other instruments and documents as they apply to Acts and subordinate legislation; and in the application of section 17(2)(a) to Acts passed or subordinate legislation made after the commencement of this Act, the reference to any other enactment includes any deed or other instrument or document.

(4) Subsections (1) and (2) of this section do not apply to Orders in Council made under section 5 of the M2 Statutory Instruments Act 1946, section 1(3) of the M3 Northern Ireland (Temporary Provisions) Act 1972 or Schedule 1 to the M4 Northern Ireland Act 1974.

Modifications etc. (not altering text)

C18 S. 23(1)(2) excluded by Northern Ireland Act 1982 (c. 38, SIF 29:3), s. 6, Sch. 2 para. 7(2)

C19 S. 23(3) excluded by Companies Act 1989 (c. 40, SIF 27), s. 144(6)

S. 23(3) excluded (6.4.2008 for specified purposes and otherwise 1.10.2009) by Companies Act 2006 (c. 46), ss. 1160(4), 1300(2); S.I. 2007/3495, art. 3(4) (subject to art. 6, Sch. 1); S.I. 2008/2860, art. 3(u) (with arts. 5, 7, 8, Sch. 2 (as amended by S.I. 2009/1802, art. 18, Sch. 2 and S.I. 2009/2476, reg. 2(3))

Marginal Citations

M2 1946 c. 36.

M3 1972 c. 22.

M4 1974 c. 28.

Valid from 01/07/1999

[F3 23A Acts of the Scottish Parliament etc. U.K.

(1) This Act applies in relation to an Act of the Scottish Parliament and an instrument made under such an Act only to the extent provided in this section.

(2) Except as provided in subsection (3) below, sections 15 to 18 apply to—

(a) an Act of the Scottish Parliament as they apply to an Act,

(b) an instrument made under an Act of the Scottish Parliament as they apply to subordinate legislation.

(3) In the application of those sections to an Act and to subordinate legislation—

(a) references to an enactment include an enactment comprised in, or in an instrument made under, an Act of the Scottish Parliament, and

(b) the reference in section 17(2)(b) to subordinate legislation includes an instrument made under an Act of the Scottish Parliament.

(4) In the application of section 20 to an Act and to subordinate legislation, references to an enactment include an enactment comprised in, or in an instrument made under, an Act of the Scottish Parliament.]

Textual Amendments

F3 S. 23A and sidenote inserted (1.7.1999) by 1998 c. 46, s. 125, Sch. 8 para. 16(2) (with s. 126(3)-(11)); S.I. 1998/3178, art. 2

Valid from 03/05/2007

[F4 23B Measures and Acts of the National Assembly for Wales etc. U.K.

(1) Subject as follows, the provisions of this Act—

(a) apply to a Measure or Act of the National Assembly for Wales as they apply to an Act, and

(b) apply to an instrument made under a Measure or Act of the National Assembly for Wales as they apply to other subordinate legislation.

(2) Sections 1 to 3 do not apply to a Measure or Act of the National Assembly for Wales.

(3) In this Act references to an enactment include an enactment comprised in, or in an instrument made under, a Measure or Act of the National Assembly for Wales.

(4) In the application of this Act to a Measure or Act of the National Assembly for Wales, references to the passing of an Act or an enactment are to be read as references to the enactment of the Measure or Act.

(5) Section 4(b) does not apply to a Measure of the National Assembly for Wales; but where such a Measure makes no provision for the coming into force of a provision contained in it, that provision comes into force at the beginning of the day on which the Measure is approved by Her Majesty in Council.]

Textual Amendments

F4 S. 23B inserted by Government of Wales Act 2006 (c. 32), s. 160(1), Sch. 10 para. 11 (with Sch. 11 para. 22), the amending provision coming into force immediately after "the 2007 election" (held on 3.5.2007) subject to s. 161(4)(5) of the amending Act, which provides for certain provisions to come into force for specified purposes at the end of "the initial period" (which ended with the first appointment of a First Minister on 25.5.2007) - see ss. 46, 161(1)(4)(5) of the amending Act

24 Application to Northern Ireland. U.K.

(1) This Act extends to Northern Ireland so far as it applies to Acts or subordinate legislation which so extend.

(2) In the application of this Act to Acts passed or subordinate legislation made after the commencement of this Act, all references to an enactment include an enactment comprised in Northern Ireland legislation whenever passed or made; and in relation to such legislation references to the passing or repeal of an enactment include the making or revocation of an Order in Council.

(3) In the application of section 14 to Acts passed after the commencement of this Act which extend to Northern Ireland, “statutory instrument” includes statutory rule for the purposes of the [F5 M5 Statutory Rules (Northern Ireland) Order 1979].

(4) The following definitions contained in Schedule 1, namely those of—

• . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F6

• The Communities and related expressions;

• The Corporation Tax Acts;

• The Income Tax Acts;

• The Tax Acts,

apply, unless the contrary intention appears, to Northern Ireland legislation as they apply to Acts.

(5) In this section “Northern Ireland legislation” means—

(a) Acts of the Parliament of Ireland;

(b) Acts of the Parliament of Northern Ireland;

(c) Orders in Council under section 1(3) of the M6 Northern Ireland (Temporary Provisions) Act 1972;

(d) Measures of the Northern Ireland Assembly; and

(e) Orders in Council under Schedule 1 to the M7 Northern Ireland Act 1974.

Textual Amendments

F5 Words substituted by S.I. 1979/1573 (N.I. 12), Sch. 4 para. 25

F6 Words repealed by British Nationality Act 1981 (c. 61, SIF 87), s. 52(8), Sch. 9

Modifications etc. (not altering text)

C20 S. 24 extended by Northern Ireland Act 1982 (c. 38, SIF 29:3), s. 6, Sch. 2 para. 7(2)

Marginal Citations

M5 S.I. 1979/1573 (N.I. 12).

M6 1972 c. 22.

M7 1974 c. 28.

25 Repeals and savings. U.K.

X1 (1) The enactments described in Schedule 3 are repealed to the extent specified in the third column of that Schedule.

(2) Without prejudice to section 17(2)(a), a reference to the M8 Interpretation Act 1889, to any provision of that Act or to any other enactment repealed by this Act, whether occurring in another Act, in subordinate legislation, in Northern Ireland legislation or in any deed or other instrument or document, shall be construed as referring to this Act, or to the corresponding provision of this Act, as it applies to Acts passed at the time of the reference.

(3) The provisions of this Act relating to Acts passed after any particular time do not affect the construction of Acts passed before that time, though continued or amended by Acts passed thereafter.

Editorial Information

X1 The text of s. 25(1), Sch. 3 is in the form in which it was originally enacted: it was not reproduced in Statutes in Force and does not reflect any repeals or amendments which may have been made prior to 1.2.1991

Marginal Citations

M8 1889 c. 63.

26 Commencement. U.K.

This Act shall come into force on 1st January 1979.

27 Short title. U.K.

This Act may be cited as the Interpretation Act 1978.