In Ward Equipment Ltd v Preston  NZCA 444, Kós P sought to cure the uncertainty around the proper approach to the implication of contractual terms by declaring the tasks of implication and interpretation as techniques of contractual construction.
Ward Equipment Ltd involved a licence agreement (Licence) between Mevon Pty Ltd (Mevon) (as licensor), and Ward Equipment Ltd (Ward) (as licensee). Mevon sought to cancel the Licence under an implied term permitting termination on reasonable notice. Ward rejected the termination on the basis that no such implied term existed.
The High Court agreed with Mevon, relying on a range of authority that it said established an inference that the Licence was terminable on reasonable notice in the absence of express provision.
In the Court of Appeal, French and Winkelmann JJ (with whom Kós P concurred), disagreed. French and Winkelmann JJ considered that, on the basis of "established principle", the correct approach was one of construction involving the application of ordinary principles. Since the Licence, among other things, had detailed provisions governing termination, the Licence left little room for the implication of the suggested term.
Kós P, in a concurring judgment, did not see the law on implication of terms as uncertain. In his Honour's view, implication, interpretation, and rectification are all techniques of construction. Kós P's view appears to be that both the traditional approach to the implication of terms reflected in BP Refinery (Westernport) Pty Ltd v Shire of Hastings(1977) 180 CLR 266 (PC), and Lord Hoffmann's more modern approach in Attorney-General of Belize v Belize Telecom Ltd  UKPC 10,  1 WLR 1988, are simply two sides of the same coin. Experience often teaches as much. In Ward Equipment, the Court was agreed that the disposition of the case was identical whichever approach the Court applied.
See the Court's decision here.