This page contains my best attempt at consolidating the various amendments to the Computer Misuse Act 1990 to show the text currently in effect. This has been done by trawling through the Statute Law Database to find relevant amendments, then modifying a working copy to apply them.
Crown Copyright material is reproduced with the permission of the Controller of HMSO and the Queen’s Printer for Scotland. Any errors are, of course, my own.
A style sheet has been used to indicate the status of the various bits of text:
An Act to make provision for securing computer material against unauthorised access or modification; and for connected purposes.
[29th June 1990]
Be it enacted by the Queen's most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:
Computer misuse offences | |
Unauthorised access to computer material | 1
(1)
A person is guilty of an offence if (2)
The intent a person has to have to commit an offence under this section need not be directed
at (3) A person guilty of an offence under this section shall be liable on summary conviction to imprisonment for a term not exceeding six months or to a fine not exceeding level 5 on the standard scale or to both. [(3) replaced 2007-10-01 (Scotland) and 2008-10-01 (elsewhere) by Police and Justice Act 2006 s.35(3).]
(3)
A person guilty of an offence under this section shall be liable |
Unauthorised access with intent to commit or facilitate commission of further offences | 2
(1)
A person is guilty of an offence under this section if he commits an offence under section 1 above ("the unauthorised access offence") with
intent (2)
This section applies to offences
(3) It is immaterial for the purposes of this section whether the further offence is to be committed on the same occasion as the unauthorised access offence or on any future occasion. (4) A person may be guilty of an offence under this section even though the facts are such that the commission of the further offence is impossible.
(5)
A person guilty of an offence under this section shall be liable
[(5) replaced 2007-10-01 (Scotland) and 2008-10-01 (elsewhere) by Police and Justice Act 2006 Sch.14]
(5)
A person guilty of an offence under this section shall be liable
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Unauthorised modification of computer material |
3
(1)
A person is guilty of an offence if
(2)
For the purposes of subsection (1)(b) above the requisite intent is an intent to cause a modification of the contents of any computer and by so doing
(3)
The intent need not be directed at
(4) For the purposes of subsection (1)(b) above the requisite knowledge is knowledge that any modification he intends to cause is unauthorised. (5) It is immaterial for the purposes of this section whether an unauthorised modification or any intended effect of it of a kind mentioned in subsection (2) above is, or is intended to be, permanent or merely temporary. (6) For the purposes of the [1971 c. 48.] Criminal Damage Act 1971 a modification of the contents of a computer shall not be regarded as damaging any computer or computer storage medium unless its effect on that computer or computer storage medium impairs its physical condition. (7)
A person guilty of an offence under this section shall be liable
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[s.3 replaced 2007-10-01 (Scotland) and 2008-10-01 (elsewhere) by Police and Justice Act 2006 s.36.] | |
Unauthorised acts with intent to impair, or with recklessness as to impairing, operation of computer, etc. |
3
(1) A person is guilty of an offence if
(2) This subsection applies if the person intends by doing the act
(3) This subsection applies if the person is reckless as to whether the act will do any of the things mentioned in paragraphs (a) to (d) [text changed 2008-10-01 by Serious Crime Act 2007 s.61(3)(b)] (c) of subsection (2) above. (4) The intention referred to in subsection (2) above, or the recklessness referred to in subsection (3) above, need not relate to
(5) In this section
(6) A person guilty of an offence under this section shall be liable
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Making, supplying or obtaining articles for use in offence under section 1 or 3 |
[s.3A added 2007-10-01 (Scotland) and 2008-10-01 (elsewhere) by Police and Justice Act 2006 s.37.] 3A (1) A person is guilty of an offence if he makes, adapts, supplies or offers to supply any article intending it to be used to commit, or to assist in the commission of, an offence under section 1 or 3. (2) A person is guilty of an offence if he supplies or offers to supply any article believing that it is likely to be used to commit, or to assist in the commission of, an offence under section 1 or 3. (3) A person is guilty of an offence if he obtains any article with a view to its being supplied for use to commit, or to assist in the commission of, an offence under section 1 or 3. (4) In this section "article" includes any program or data held in electronic form. (5) A person guilty of an offence under this section shall be liable
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Jurisdiction | |
[Note changed 2007-10-01 (Scotland) and 2008-10-01 (elsewhere)
by Police and Justice Act 2006 Sch.14.] Territorial scope of offences under this Act offences under sections 1 to 3 |
4
(1)
Except as provided below in this section, it is immaterial for the purposes of any offence under section 1 or 3 above
(2) Subject to subsection (3) below, in the case of such an offence at least one significant link with domestic jurisdiction must exist in the circumstances of the case for the offence to be committed. (3) There is no need for any such link to exist for the commission of an offence under section 1 above to be established in proof of an allegation to that effect in proceedings for an offence under section 2 above. (4)
Subject to section 8 below, where
(5) This section is without prejudice to any jurisdiction exercisable by a court in Scotland apart from this section. (6)
References in this Act to the home country concerned are references
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Significant links with domestic jurisdiction | 5 (1) The following provisions of this section apply for the interpretation of section 4 above. (2)
In relation to an offence under section 1, either of the following is a significant link with domestic jurisdiction
(3)
In relation to an offence under section 3, either of the following is a significant link with domestic jurisdiction
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[Note changed 2008-10-01 by Police and Justice Act 2006 Sch.14.] Territorial scope of inchoate offences related to offences under this Act offences under sections 1 to 3 |
6
(1)
On a charge of conspiracy to commit an
offence under this Act
[Text changed 2008-10-01 by Police and Justice Act 2006 Sch.14.]
offence under section 1, 2 or 3 above
the following questions are immaterial to the accused's guilt
(2)
On a charge of attempting to commit an offence under section 3 above the following questions are immaterial to the accused's guilt
(3)
[(3) repealed 2008-10-01 by Serious Crime Act 2007 Sch.6 and 14] (4) This section does not extend to Scotland. |
Territorial scope of inchoate offences related to offences under external law corresponding to offences under this Act [Note changed 2008-10-01 by Police and Justice Act 2006 Sch.14.] offences under sections 1 to 3 |
7 (1)
[(1) repealed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(2) and Sch.2] (1A) Subject to section 8 of the Computer Misuse Act 1990 (relevance of external law), if this subsection applies to an agreement, this Part of this Act has effect in relation to it as it has effect in relation to an agreement falling within subsection (1) above. (1B)
Subsection (1A) above applies to an agreement if
(2)
[(2) repealed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(2) and Sch.2] (5) In the application of this Part of this Act to an agreement to which subsection (1A) above applies any reference to an offence shall be read as a reference to what would be the computer misuse offence in question but for the fact that it is not an offence triable in England and Wales. (6) In this section "computer misuse offence" means an offence under the Computer Misuse Act 1990. (3) The following subsections shall be inserted after section 1(1) of the [1981 c. 47.] Criminal Attempts Act 1981 (1A) Subject to section 8 of the Computer Misuse Act 1990 (relevance of external law), if this subsection applies to an act, what the person doing it had in view shall be treated as an offence to which this section applies. (1B)
Subsection (1A) above applies to an act if
(4)
[(4) repealed 2008-10-01 by Serious Crime Act 2007 Sch.6 and 14] |
Relevance of external law | 8 (1) A person is guilty of an offence triable by virtue of section 4(4) above only if what he intended to do or facilitate would involve the commission of an offence under the law in force where the whole or any part of it was intended to take place. (2)
[(2) repealed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(2), Sch.1, and Sch.2] (3) A person is guilty of an offence triable by virtue of section 1(1A) of the [1981 c. 47.] Criminal Attempts Act 1981 [Text repealed 2008-10-01 by Serious Crime Act 2007 Sch.6 and 14] or by virtue of section 7(4) above only if what he had in view would involve the commission of an offence under the law in force where the whole or any part of it was intended to take place. (4) Conduct punishable under the law in force in any place is an offence under that law for the purposes of this section, however it is described in that law. (5)
Subject to subsection (7) below, a condition specified in
any of subsections (1) to (3)
[Text changed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(2) and Sch.1]
subsection (1) or (3)
above shall be taken to be satisfied unless not later than rules of court may provide the defence serve on the prosecution a notice
(6)
In subsection (5) above "the relevant conduct" means
(7) The court, if it thinks fit, may permit the defence to require the prosecution to show that the condition is satisfied without the prior service of a notice under subsection (5) above. (8) If by virtue of subsection (7) above a court of solemn jurisdiction in Scotland permits the defence to require the prosecution to show that the condition is satisfied, it shall be competent for the prosecution for that purpose to examine any witness or to put in evidence any production not included in the lists lodged by it. (9) In the Crown Court the question whether the condition is satisfied shall be decided by the judge alone. (10) In the High Court of Justiciary and in the sheriff court the question whether the condition is satisfied shall be decided by the judge or, as the case may be, the sheriff alone. |
British citizenship immaterial | 9 (1) In any proceedings brought in England and Wales in respect of any offence to which this section applies it is immaterial to guilt whether or not the accused was a British citizen at the time of any act, omission or other event proof of which is required for conviction of the offence. (2)
This section applies to the following offences
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Miscellaneous and general | |
Saving for certain law enforcement powers | 10
Section 1(1) above has effect without prejudice to the operation
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Proceedings for offences under section 1 |
[s.11 repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] 11 (1)
[(1) repealed 2005-04-01 by Courts Act 2003 c.39 Sch.8 and Sch.10] (2) Subject to subsection (3) below, proceedings for an offence under section 1 above may be brought within a period of six months from the date on which evidence sufficient in the opinion of the prosecutor to warrant the proceedings came to his knowledge. (3) No such proceedings shall be brought by virtue of this section more than three years after the commission of the offence. (4) For the purposes of this section, a certificate signed by or on behalf of the prosecutor and stating the date on which evidence sufficient in his opinion to warrant the proceedings came to his knowledge shall be conclusive evidence of that fact. (5)
A certificate stating that matter and purporting to be so signed shall be deemed to be so signed unless the contrary is proved. (6)
[(6) repealed 1999-09-27 by Access to Justice Act 1999 c.22 ss.106, 108(3)(f), Sch.14, and Sch.15] (7) This section does not extend to Scotland. |
Conviction of an offence under section 1 in proceedings for an offence under section 2 or 3 |
[s.12 repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] 12
(1)
If on the trial on indictment of a person charged with
(2) The Crown Court shall have the same powers and duties in relation to a person who is by virtue of this section convicted before it of an offence under section 1 above as a magistrates' court would have on convicting him of the offence. (3) This section is without prejudice to section 6(3) of the [1967 c. 58.] Criminal Law Act 1967 (conviction of alternative indictable offence on trial on indictment). (4) This section does not extend to Scotland. |
Proceedings in Scotland | 13
(1)
A sheriff shall have jurisdiction in respect of an offence under section 1 or 2 above if
(2)
A sheriff shall have jurisdiction in respect of an offence under section 3 above if
(3)
[(3) repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] (4)
[(4) repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] (5)
[(5) repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] (6)
[(6) repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] (7)
[(7) repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] (8) In proceedings in which a person is charged with an offence under section 2 or 3 above and is found not guilty or is acquitted of that charge, he may be found guilty of an offence under section 1 above if on the facts shown he could have been found guilty of that offence in proceedings for that offence [Text repealed 2007-10-01 by Police and Justice Act 2006 Sch.14.] commenced before the expiry of any time limit under this section applicable to such proceedings. (9) Subsection (8) above shall apply whether or not an offence under section 1 above has been libelled in the complaint or indictment. (10) A person found guilty of an offence under section 1 above by virtue of subsection (8) above shall be liable, in respect of that offence, only to the penalties set out in section 1. (11) This section extends to Scotland only. |
Search warrants for offences under section 1 |
[s.14 repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] 14
(1)
Where a circuit judge is satisfied by information on oath given by a constable that there are reasonable grounds for believing
(2) The power conferred by subsection (1) above does not extend to authorising a search for material of the kinds mentioned in section 9(2) of the [1984 c. 60.] Police and Criminal Evidence Act 1984 (privileged, excluded and special procedure material). (3)
A warrant under this section
(4)
In executing a warrant issued under this section a constable may seize an article if he reasonably believes that it is evidence that an offence under section 1 above has been or is about to be committed.
(5) In this section "premises" includes land, buildings, movable structures, vehicles, vessels, aircraft and hovercraft. (6) This section does not extend to Scotland. |
Extradition where Schedule 1 to the Extradition Act 1989 applies |
[s.15 repealed 2004-01-01 by Extradition Act 2003 c.41 Sch.3 and 4] 15
The offences to which an Order in Council under section 2 of the [1870 c. 52.] Extradition Act 1870 can apply shall include
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Application to Northern Ireland | 16
(1)
The following provisions of this section have effect for applying this Act in relation to Northern Ireland with the modifications there mentioned. (1A)
[(1A) added 2008-10-01 by Police and Justice Act 2006 Sch.14] (2)
In section 2(2)(b)
(2A)
[(2A) added 2008-10-01 by Police and Justice Act 2006 Sch.14] (3)
[(3) repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] (3A)
[(3A) added 2008-10-01 by Police and Justice Act 2006 Sch.14] (3B)
[(3B) added 2008-10-01 by Police and Justice Act 2006 Sch.14] (4)
Subsections (5) to (7) below apply in substitution for subsections (1) to (3) of section 7;
[Text changed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(1) and Sch.1]
Subsection (7) below shall apply in substitution for subsection (3) of section 7
; [Text repealed 2008-10-01 by Serious Crime Act 2007 Sch.6 and 14]
and any reference in subsection (4) of that section to England and Wales shall be read as a reference to Northern
Ireland.
(5)
[(5) repealed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(1), Sch.1, and Sch.2] (1A) Subject to section 8 of the Computer Misuse Act 1990 (relevance of external law), if this paragraph applies to an agreement, this Part has effect in relation to it as it has effect in relation to an agreement falling within paragraph (1). (1B)
Paragraph (1A) applies to an agreement if
(6)
[(6) repealed 1998-09-04 by Criminal Justice (Terrorism and Conspiracy) Act 1998 c.40 s.9(1), Sch.1, and Sch.2] (5) In the application of this Part to an agreement to which paragraph (1A) applies any reference to an offence shall be read as a reference to what would be the computer misuse offence in question but for the fact that it is not an offence triable in Northern Ireland. (6) In this Article "computer misuse offence" means an offence under the Computer Misuse Act 1990. (7) The following paragraphs shall be inserted after Article 3(1) of that Order (1A) Subject to section 8 of the Computer Misuse Act 1990 (relevance of external law), if this paragraph applies to an act, what the person doing it had in view shall be treated as an offence to which this Article applies. (1B)
Paragraph (1A) above applies to an act if
(8)
In section 8 (9) The references in sections 9(1) and 10 to England and Wales shall be read as references to Northern Ireland. (10)
[(10) repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] (1)
A magistrates' court for a county division in Northern Ireland may hear and determine a complaint charging an offence under section 1 above or conduct a preliminary investigation or preliminary inquiry into an offence under that section if
[Text repealed 2005-04-01 by Courts Act 2003 c.39 Sch.8 and Sch.10] (11)
[(11) repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] (12)
[(12) repealed 2008-10-01 by Police and Justice Act 2006 Sch.14] |
Northern Ireland: search warrants for offences under section 1 |
[s.16A added 2008-10-01 by Police and Justice Act 2006 Sch.14] 16A
(1) Where a county court judge is satisfied by information on oath given by a constable that there are reasonable grounds for believing (2) The power conferred by subsection (1) above does not extend to authorising a search for material of the kinds mentioned in Article 11(2) of the Police and Criminal Evidence (Northern Ireland) Order 1989 (privileged, excluded and special procedure material). (3) A warrant under this section
(a) may authorise persons to accompany any constable executing the warrant; and (4) In exercising a warrant issued under this section a constable may seize an article if he reasonably believes that it is evidence that an offence under section 1 above has been or is about to be committed. (5) In this section "premises" includes land, buildings, movable structures, vehicles, vessels, aircraft and hovercraft. (6) This section extends only to Northern Ireland. |
Interpretation | 17 (1) The following provisions of this section apply for the interpretation of this Act. (2)
A person secures access to any program or data held in a computer if by causing a computer to perform any function he
(3)
For the purposes of subsection (2)(c) above a person uses a program if the function he causes the computer to perform
(4)
For the purposes of subsection (2)(d) above
(5)
Access of any kind by any person to any program or data held in a computer is unauthorised if
(6)
References to any program or data held in a computer include references to any program or data held in any removable storage medium which is for the time being in the computer; and a computer is to be regarded as containing any program or data held in any such medium. (7)
[(7) repealed 2008-10-01 by Police and Justice Act 2006 Sch.14.] (8)
Such a modification is unauthorised if
[(8) replaced 2007-10-01 (Scotland) and 2008-10-01 (elsewhere) by Police and Justice Act 2006 Sch.14.] (8)
An act done in relation to a computer is unauthorised if the person doing the act (or causing it to be done)
(a) is not himself a person who has responsibility for the computer and is entitled to determine whether the act may be done; and (9) References to the home country concerned shall be read in accordance with section 4(6) above. (10) References to a program include references to part of a program. |
Citation, commencement | 18 (1) This Act may be cited as the Computer Misuse Act 1990. (2) This Act shall come into force at the end of the period of two months beginning with the day on which it is passed. (3) An offence is not committed under this Act unless every act or other event proof of which is required for conviction of the offence takes place after this Act comes into force. |