Computer Misuse Act 1990

Computer misuse offences

1 Unauthorised access to computer material

(1) A person is guilty of an offence if—

(a) he causes a computer to perform any function with intent to secure access to any program or data held in any computer;

(b) the access he intends to secure is unauthorised; and

(c) he knows at the time when he causes the computer to perform the function that that is the case.

(2) The intent a person has to have to commit an offence under this section need not be directed at—

(a) any particular program or data;

(b) a program or data of any particular kind; or

(c) a program or data held in any particular computer.

(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.

2 Unauthorised access with intent to commit or facilitate commission of further offences

(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—

(a) to commit an offence to which this section applies; or

(b) to facilitate the commission of such an offence (whether by himself or by any other person);

and the offence he intends to commit or facilitate is referred to below in this section as the further offence.

(2) This section applies to offences—

(a) for which the sentence is fixed by law; or

(b) for which a person of twenty-one years of age or over (not previously convicted) may be sentenced to imprisonment for a term of five years (or, in England and Wales, might be so sentenced but for the restrictions imposed by section 33 of the [1980 c. 43.] Magistrates' Courts Act 1980).

(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—

(a) on summary conviction, to imprisonment for a term not exceeding six months or to a fine not exceeding the statutory maximum or to both; and

(b) on conviction on indictment, to imprisonment for a term not exceeding five years or to a fine or to both.

3 Unauthorised modification of computer material

(1) A person is guilty of an offence if—

(a) he does any act which causes an unauthorised modification of the contents of any computer; and

(b) at the time when he does the act he has the requisite intent and the requisite knowledge.

(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—

(a) to impair the operation of any computer;

(b) to prevent or hinder access to any program or data held in any computer; or

(c) to impair the operation of any such program or the reliability of any such data.

(3) The intent need not be directed at—

(a) any particular computer;

(b) any particular program or data or a program or data of any particular kind; or

(c) any particular modification or a modification of any particular kind.

(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—

(a) on summary conviction, to imprisonment for a term not exceeding six months or to a fine not exceeding the statutory maximum or to both; and

(b) on conviction on indictment, to imprisonment for a term not exceeding five years or to a fine or to both.