Chapter 2 Key facts checklist

Agreement Problems

The terms of an agreement must be sufficiently certain or the agreement will be void for uncertainty. Agreements for the parties to agree a matter, such as the price, will generally lack the necessary certainty. However, if nothing is said about the price, then statute will imply a reasonable price.
If there is uncertainty so that no contract results, in some circumstances there may nevertheless be an obligation to pay the reasonable value for requested performance (a quantum meruit).
An agreement mistake will occur where one or both of the parties allege that they made a fundamental mistake as to a term which prevents agreement. Such a mistake means that the contract is void. Alternatively a contract may be voidable for a mistake as to attributes and this protects innocent third parties who have acquired the contract goods.
It may be possible to rectify a written record of an agreement where there is a transcription mistake in recording that agreement accurately. The plea of non est factum ('this is not my deed') may very rarely be available where it is claimed that a signed document has been signed by mistake because the document is fundamentally different in nature to the document believed to have been signed.