Unilateral offer
A unilateral offer is one where one party promises something in return for some action on the part of another party. In relation to unilateral offers, revocation is not permissible once the offeree has started performing the task requested.
Reward cases are examples of such unilateral promises. There is no compulsion placed on the party undertaking the action but it would seem to be unfair if the promisor were entitled to revoke their offer just before the offeree was about to complete their part of the contract. An example of unilateral contracts may be seen in Carlill v Carbolic Smoke Ball Co (1993), where the company promised to pay £100 to anyone who caught infl uenza after using their product. No one was forced to buy the product but once they did and started using it, the company was bound by its promise. In Errington v Errington (1952), a father promised his son and daughter-in-law that he would convey a house to them when they had paid off the outstanding mortgage. After the father’s death, his widow sought to revoke the promise. It was held that the promise could not be withdrawn as long as the mortgage payments continued to be met. |
