Computer Misuse Act 1990

the info you need

what is it

An Act to make provision for securing computer material against unauthorised access or modification; and for connected purposes.

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 , or to enable any such access to be secured ;

(b)the access he intends to secure, or to enable to be secured, 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—

(a)on summary conviction in England and Wales, to imprisonment for a term not exceeding 12 months or to a fine not exceeding the statutory maximum or to both;

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

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

The bill, supported by the government, became used in 1990. Sections 1-3 of the Act introduced three criminal offences:

  1. unauthorised access to computer material, punishable by 6 months' imprisonment or a fine of £5000
  2. unauthorised access with intent to commit or facilitate commission of further offences, punishable by 6 months maximum fine on summary conviction or 5 years fine on indictment;
  3. unauthorised modification of computer material, subject to the same sentences as section 2 offences.