16. Mistake as to terms or mistake as to quality.

Where the parties do not in fact agree on what is the subject matter of the contract, for example because A intends to sell one thing, and B to buy another1, then, subject to the operation of the doctrine of estoppel2, there is no contract between them. The same result follows where the parties do not in fact agree on what are the terms of the agreement3.

A mistake as to the terms of the offer must be carefully distinguished from a mistake as to the quality4 of what is being offered5. A mistake as to the terms which are