Ward v. Byham  1 WLR 496, Court of Appeal
The plaintiff and the defendant were, respectively, mother and father to a child. After they had lived together as partners for several years, and the plaintiff had given birth to an illegitimate child, the defendant turned the plaintiff out of the family home. Initially, the defendant put the child into the care of a neighbour for which he paid £1 per week. When the plaintiff found a new home for herself, she agreed with the defendant that she would care for the child and that he would pay her £1 per week. Subsequently, the plaintiff remarried and the defendant ceased payment. The plaintiff brought an action against the defendant on the basis of his undertaking to pay her £1 per week. The defendant denied that he was liable to make the promised payments on the ground that his promise to pay her was not supported by consideration. The Court of Appeal held that the plaintiff had provided consideration for the defendant’s promise with the result that the defendant was liable to make the promised payment.
Denning LJ [set out the facts of the case and continued]
I approach the case, therefore, on the footing that, in looking after the child, the mother is only doing what she is legally bound to do. Even so, I think that there was sufficient consideration to support the promise. I have always thought that a promise to perform an existing duty, or the performance of it, should be regarded as good consideration, because it is a benefit to the person to whom it is given. Take this very case. It is as much a benefit for the father to have the child looked after by the mother as by a neighbour. If he gets the benefit for which he stipulated, he ought to honour his promise, and he ought not to avoid it by saying that the mother was herself under a duty to maintain the child. I regard the father’s promise in this case as what is sometimes called a unilateral contract, a promise in return for an act, a promise by the father to pay £1 a week in return for the mother’s looking after the child. Once the mother embarked on the task of looking after the child, there was a binding contract. So long as she looked after the child, she would be entitled to £1 a week . . . I would dismiss the appeal.
It seems to me . . . that the father was saying, in effect: Irrespective of what may be the strict legal position, what I am asking is that you shall prove that Carol [the child] will be well looked after and happy, and also that you must agree that Carol is to be allowed to decide for herself whether or not she wishes to come and live with you. If those conditions were fulfilled the father was agreeable to pay. Upon those terms, which in fact became operative, the father agreed to pay £1 a week. In my judgment, there was ample consideration there to be found for his promise, which I think was binding.
I have come to the same conclusion. I think that the letter of July 27, 1954, clearly expresses good consideration for the bargain, and for myself I am content to adopt the very careful judgment of the learned county court judge.