Australia
In all Australian jurisdictions, a representative proceeding, or class action (as it is more commonly known in Australia) may be commenced by or against any one person as a representative of numerous persons (the minimum number required is generally seven people) who have the same interest in the proceeding and the claims brought give rise to a substantial common issue of law or fact. It is possible to commence a class action against multiple defendants and there is no requirement for every group member to have a claim against every defendant.
An overarching consideration of the courts in hearing a representative proceeding is whether it involves less delay, expense, and prejudice to the parties than alternative forms of trial. If not, the court may discontinue the proceedings.
The Federal, New South Wales, Victorian and, most recently, Queensland jurisdictions contain further statutory provisions in relation to representative proceedings, which are arguably more liberal and plaintiff-friendly than other jurisdictions. These jurisdictions allow representative proceedings to be brought where seven or more people have claims which arise out of the same or related circumstances and give rise to a substantial common issue of fact or law. Over 90% of all class actions filed in Australia from 1992-2009 were filed in the Federal Court of Australia.
When a representative proceeding is commenced, all potential plaintiffs who fall within a class become members of the class, whether they are aware of the claim or not. Members can then opt out of the proceedings before a date set by the court. All class members who do not opt out will be bound by the judgment of the court or by any approved settlement.
It is important to note that, although some states have yet to formally abolish the law of champerty and maintenance, outside of the US, Australia has one of the most developed class action industries, with a variety of large, class action plaintiff law firms and with many litigation funders having been active in the jurisdiction for over 20 years. This active funding industry has seen a continued increase in the number of class actions being commenced in Australia.