4 Computer Misuse Act 1990 (c. 18) Document Generated: 2022-03-08 Changes to legislation: Computer Misuse Act 1990 is up to date with all changes known to be in force on or before 08 March 2022. There are changes that may be brought into force at a future date. Changes that have been made appear in the content and are referenced with annotations. (See end of Document for details) View outstanding changes (c) on conviction on indictment, to imprisonment for a term not exceeding ten years or to a fine or to both. Textual Amendments F7 F8 F9 F10 F11 S. 3 substituted (1.10.2007 for S. and 1.10.2008 otherwise) by Police and Justice Act 2006 (c. 48), ss. 36, 53 (with s. 38(3)(4)(6)); S.S.I. 2007/434, art. 2; S.I. 2008/2503, art. 2 (the substituting provision being amended for E.W.N.I. (1.10.2008) by 2007 c. 27, ss. 61(3), 94 (with Sch. 13 para. 5); S.I. 2008/2504, art. 2(a)) Word at the end of s. 3(2)(b) inserted (E.W.N.I.) (1.10.2008) by virtue of Serious Crime Act 2007 (c. 27), ss. 61(3)(a)(i), 94 (with Sch. 13 para. 5); S.I. 2008/2504, art. 2(a) S. 3(2)(d) and preceding word repealed (E.W.N.I.) (1.10.2008) by virtue of Serious Crime Act 2007 (c. 27), ss. 61(3)(a)(ii), 92, 94, Sch. 14 (with Sch. 13 para. 5); S.I. 2008/2504, art. 2(a)(i)(viii) S. 3(3): Words "to (c)" substituted for words "to (d)" (E.W.N.I.) (1.10.2008) by virtue of Serious Crime Act 2007 (c. 27), ss. 61(3)(b), 94 (with Sch. 13 para. 5); S.I. 2008/2504, art. 2(a) Word in s. 3(6)(b) substituted (3.5.2015) by Serious Crime Act 2015 (c. 9), s. 88(1), Sch. 4 para. 7(c); S.I. 2015/820, reg. 2(r)(iii) [F123ZA Unauthorised acts causing, or creating risk of, serious damage (1) A person is guilty of an offence if— (a) the person does any unauthorised act in relation to a computer; (b) at the time of doing the act the person knows that it is unauthorised; (c) the act causes, or creates a significant risk of, serious damage of a material kind; and (d) the person intends by doing the act to cause serious damage of a material kind or is reckless as to whether such damage is caused. (2) Damage is of a “material kind” for the purposes of this section if it is— (a) damage to human welfare in any place; (b) damage to the environment of any place; (c) damage to the economy of any country; or (d) damage to the national security of any country. (3) For the purposes of subsection (2)(a) an act causes damage to human welfare only if it causes— (a) loss to human life; (b) human illness or injury; (c) disruption of a supply of money, food, water, energy or fuel; (d) disruption of a system of communication; (e) disruption of facilities for transport; or (f) disruption of services relating to health. (4) It is immaterial for the purposes of subsection (2) whether or not an act causing damage— (a) does so directly; (b) is the only or main cause of the damage. (5) In this section— (a) a reference to doing an act includes a reference to causing an act to be done;