Legal latin the principle that an arbitral tribunal’s jurisdiction ends when it has fulfilled the terms of reference of the tribunal. The extent of the closure and its time-frame usually depend on the rules of the arbitration organisation. Once a tribunal is functus officio substantial changes or revisions to any award made by the tribunal are usually precluded. Generally addressing issues not covered in the award, or fixing typographical errors may be permitted. Interim awards may, if not carefully be drafted, render the tribunal functus officio with respect to the subject of that interim award – so care should be taken to consider if an interim award might be a final award on the issue.