Oct 22, 2012
It is a Latin phrase. Black's Law Dictionary defines the phrase as “having fulfilled the function, discharged the office, or accomplished the purpose, and therefore of no further force or authority. An officer or agency whose mandate has expired either because of the arrival of an expiry date or because an agency has accomplished the purpose for which it was created".
Ruby, C., at al (2008), defined functus officio, inter alia, as “... having discharged a duty”
In Chandler v Alberta Association of Architects  2 SCR 848, Justice Sopinka, in relation to the principle of functus officio states that the general rule is that a final decision of a court cannot be reopened.... "The rule applied only after the formal judgment had been drawn up, issued and entered, and was subject to two exceptions: where there had been a slip in drawing it up, and where there was an error in expressing the manifest intention of the court."
In Malaysia, the principle of functus officio is set out in New India Assurance Co. Ltd v. Karam Singh  1 LNS 155 where Gill FJ states (at pp. 156-157):
“Functus officio means a person who has discharged his duty, or whose office of authority is at an end (see Bedwell v. Wood 918770 2 QBD). Thus, once a president has convicted a person in charged with an offence before him, he is functus officio, and cannot rescind the sentence or re-try the case. Similarly, once he has tried a civil action and made an order on the final determination of the dispute between the parties, he is functus officio and cannot rescind his final order and re-try the case, or try a subsequent action between the same parties on the same subject matter. In the present case, the learned president became functus officio as regards the earlier action on his refusing the plaintiff’s application for its reinstatement, but he certainly did not become functus officio as regards the real dispute between the parties which he never tried, the issue between the parties being whether the plaintiffs were entitled to recover the money which they alleged they had paid to the defendant under a mistake of fact. In other words, he was not functus officio 1 as regards that issue between the same parties in the second action. He was therefore wrong in dismissing the action”.
In Mena Narvaez and others v. The Minister of Citizenship and Immigration 2009 FC 514, the judge said,"The principle of functus officio is based upon the finality of judgments and jurisdiction once a formal decision is rendered, signed and communicated to the parties, it cannot be re-opened”.
In OCBC Bank (Malaysia) Bhd v. Delightful Strength Sdn Bhd  3 CLJ 297, James Fong (High Court of Malaya) (27 May 2004), states,
“I shall first deal with the defence of functus officio. In respect of the proposed amendment to the order for sale, I am of the view that this defence is unsustainable. The general proposition that the same court that issued the order for sale has no power to alter or vary its own order after it is drawn up and perfected does not apply to any proposed amendment made under the slip rule of Order 20 r 11 of the RHC — see the judgment of MT Chang FJ in Hock Hua Bank Bhd v Sahari Murid  1 MLJ 143”.