Contracts in UK Law

The general presumption is that the parties have expressed every material term which they intended should govern their agreement, whether oral or in writing. But it is well recognised that there may be cases where obviously some term must be implied if the intention of the parties is not to be defeated, some term of which it can be predicated that "it goes without saying", some term not expressed but necessary to give to the transaction such business efficacy as the parties must have intended.

There are certain contracts expressed by the law to be contracts of the utmost good faith where material facts must be disclosed; if not the contract is voidable. Apart from special fiduciary relationships contracts for partnership and contracts of insurance are the leading instances. In such cases the duty does not arise out of contract; the duty of a person proposing an insurance arises before a contract is made; so of an intending partner.

The fact that a particular construction leads to a very unreasonable result must be a relevant consideration. The more unreasonable the result the more unlikely it is that the parties can have intended it, and if they do intend it the more necessary it is that they shall make that intention abundantly clear.

If there are two possible constructions, the court is entitled to prefer the construction which is consistent with business common sense and to reject the other.

(1) Interpretation is the ascertainment of the meaning which the document would convey to a reasonable person having all the background knowledge which would reasonably have been available to the parties in the situation in which they were at the time of the contract.

So perhaps it would be simpler to say at the outset that frustration occurs whenever the law recognises that without default of either party a contractual obligation has become incapable of being performed because the circumstances in which performance is called for would render it a thing radically different from that which was undertaken by the contract.

If one approaches the question by reference to what the parties would have agreed, one is not strictly concerned with the hypothetical answer of the actual parties, but with that of notional reasonable people in the position of the parties at the time at which they were contracting. Secondly, a term should not be implied into a detailed commercial contract merely because it appears fair or merely because one considers that the parties would have agreed it if it had been suggested to them.