A person on a premises who does not leave immediately when asked by an authorised person (or comes back within the following 24 hours), is guilty of an offence that has a maximum penalty of a fine of $2500 or imprisonment for six months [Summary Offences Act 1953 s 17A]. Even harsher penalties can apply to 'gatecrashers' or univited guests at parties held on private premises under s 17AB, see GATECRASHING AND PARTIES.
It is an offence to use offensive language or behave in an offensive manner while trespassing on premises, with a maximum fine of $1250. The same fine applies if a trespasser refuses to give his or her name and address when asked by an authorised person.
An authorised person who asks a trespasser to leave premises or to give his or her name and address must in turn tell the trespasser his or her name and address and official capacity. A person who falsely pretends to a trespasser, by word or action, to be an authorised person is guilty of an offence and liable to a maximum fine of $750.