Functus officio definition
Functus officio means that, subject to exceptions, a case cannot be reopened because it has ended and the Court has exhausted its purpose: R v Riddle,
Functus officio means official functional or operational
Functus officio means simply ‘having performed the office’ and is a long established principle of administrative law. It serves to ensure finality in that a decision making process has a defined end point. This, in turn, allows for the commencement of any appeal or review process. If a decision can be altered or amended without limitation, then the legal rights and obligations which flow from it can never be said to be certain. It, along with the doctrine of res judicata, serves to promote the strong public interest in finality.