The formal charge of an offence is called an Information. Prior to 3 October 2017 the formal charge of most summary offences was called a Complaint.

An Information can be laid personally or by a legal practitioner, or other person duly authorised to lay the information on the informant's behalf, also known as prosecution. For a summary offence (where the defendant has not been arrested) that can be done by filing a Form 2 Information and Summons at the Magistrates Court via the CourtSA portal [Criminal Procedure Act 1921 (SA) s 49; Joint Criminal Rules 2022 (SA) r 62.1].

If the informant is not a public authority [see r 2.1 for definition] the form must be signed by an attesting witness.

When filing an Information, the informant must identify the location at which the applicant requests that the proceeding be heard, at a location which the Court sits and either close to where the offence or one of the offences charged was allegedly committed, or where the defendant lives [ r 62.1 (12]. The Court will consider the request in listing the first hearing, but it is in the discretion of the Court as to the location of the first hearing. It is also in the discretion of the Court as to the location of any subsequent hearings or of any trial.

For summary offences the time limit within which to issue an information is six months if an expiation notice has been given for the offence (from the expiry of the expiation period specified in the notice) but for any other summary offence the time limit will be two years (of the date on which the offence is alleged to have been committed) [Criminal Procedure Act 1921 (SA) s 52].

A private citizen who lays an information must carry on the prosecution. However, most prosecutions for summary offences are begun by, and in the name of, the police. The prosecution is conducted either by a police prosecutor or a lawyer employed by the police. Certain government departments and agencies, such as the Department of Transport, Energy and Infrastructure and Consumer and Business Services, the Department of Primary Industry and Fisheries, Safework SA and others employ their own legal officers or use lawyers from the Crown Solicitor's Office for this purpose, for example for prosecutions in relation to fisheries and native vegetation offences.

The police have considerable discretion in deciding whether or not to prosecute a complaint. Although it may strongly appear that a person is guilty of an offence, it is the job of the prosecutor to consider the available evidence and they may decide not to go ahead with the charge for a number of reasons, such as: