"65. Ascertaining the existence and terms of an oral contract is a question of fact...
66. Consideration of surrounding circumstances and post contractual conduct is permissible when the existence or terms of an oral contract are in issue...
67. Spigelman CJ explained in County Securities Pty Ltd v Challenger Group Holdings Pty Ltd [2008] NSWCA 193 at [7]:
"The subject matter and the concomitant terms of the [oral] contract must be inferred from a combination of surrounding circumstances including conversations, documents and conduct none of which provide a definitive form of words. The issue is not one of interpretation, because there are no words to interpret. The issue is one of fact: what did the parties agree?"
68. In Brambles Holdings Ltd v Bathurst City Council (2001) 53 NSWLR 153, Heydon JA (as his Honour then was) observed:
"…a contract may be inferred from the acts and conduct of parties as well as or in the absence of their words … The question in this class of case is whether the conduct of the parties, viewed in the light of the surrounding circumstances, shows a tacit understanding or agreement … The conduct of the parties, however, must be capable of proving all the essential elements of an express contract … Care must also be taken not to infer anterior promises from conduct which represents no more than an adjustment of their relationship in the light of changing circumstances … Moreover, in an ongoing relationship, it is not always easy to point to the precise moment when the legal criteria of a contract have been fulfilled. Agreements concerning terms and conditions which might be too uncertain or too illusory to enforce at a particular time in the relationship may by reason of the parties' subsequent conduct become sufficiently specific to give rise to legal rights and duties. In a dynamic commercial relationship new terms will be added or will supersede older terms. It is necessary therefore to look at the whole relationship and not only at what was said and done when the relationship was first formed."
69. In Branir Pty Ltd v Owston Nominees (No 2) Pty Ltd (2001) 117 FCR 424, Allsop J (as he then was) similarly explained:
"[Contracts] can also arise when business people speak and act and order their affairs in a way without necessarily stopping for the formalities of dotting i's and crossing t's or where they think they have done so … Sometimes this failure occurs because, having discussed the commercial essentials and having put in place necessary structural matters, the parties go about their commercial business on the clear basis of some manifested mutual assent, without ensuring the exhaustive completeness of documentation. In such circumstances, even in the absence of clear offer and acceptance, and even without being able (as one can here) to identify precisely when a contract arose, if it can be stated with confidence that by a certain point the parties mutually assented to a sufficiently clear regime which must, in the circumstances, have been intended to be binding, the court will recognise the existence of a contract. Sometimes this is said to be a process of inference or implication. For my part, I would see it as the inferring of a real intention expressed through, or to be found in, a body of conduct, including, sometimes, communications, even if it be the case that the parties did not consciously advert to, or discuss, some aspect of the relationship and say: 'and we hereby agree to be bound/ in this or that respect. The essential question in such cases is whether the parties' conduct, including what was said and not said and including the evident commercial aims and expectations of the parties, reveals an understanding or agreement or, as sometimes expressed, a manifestation of mutual assent, which bespeaks an intention to be legally bound to the essential elements of a contract." (citations omitted)
- In Highfields Australia Pty Ltd v Advanced Motor Dealers Group Pty Ltd (Received and Manager Appointed) [2023] NSWSC 1458, Richmond J summarised principles relevant to the determination of the existence of an oral contract and its terms [5] (citations omitted):
"113. Where the existence and terms of an oral contract is in issue, consideration of the surrounding circumstances including the history of the relationship between the parties and their conduct prior to and at the time the alleged contract was entered into is permissible, as well as post-contractual conduct.
…
115. It is for this reason that where the events (including conversations) relied upon took place many years ago, it is recognised that "the only safe course is to place primary emphasis on the objective factual surrounding material and the inherent commercial probabilities together with the documentation tendered in evidence".
- More generally, when ascertaining what the parties agreed, the Court must consider what the words and conduct of the parties would have led a reasonable person in the position of the other party to believe who had knowledge of all the background circumstances then known and reasonably available to the parties. The intention of the parties is objectively ascertained and not by reference to their subjective intentions or beliefs: Realestate.com.au Pty Ltd v Hardingham (2022) 277 CLR 115 at [15], [47] and [48].