This article is about consideration under English law. For an American focused article, see Consideration in American law. Consideration in English law is one of the four consideration in business law pdf building blocks of a contract. If only one party offers consideration, the agreement is not legally a binding contract.
In other words, if an arrangement consists of a promise which is not supported by consideration, then the arrangement is not a legally enforceable contract. Mutual promises constitute consideration for each other.
The consideration must be executory or executed, but not past. Consideration is executory when a promise to do something in the future is given in exchange for another promise to be done in the future. Consideration is executed when a promise is actually executed, in exchange for another promise to be executed in the future.