Pinnel's Case  5 Co. Rep. 117a, also known as Penny v Cole, is an important case in English contract law, on the doctrine of part performance. In it, Sir Edward Coke opined that a part payment of a debt could not extinguish the obligation to pay the whole.
Pinnel sued Cole, in an action of debt upon a bond, for the sum of £8 10s. The defendant, Cole, argued he had, at Pinnel's request, tendered £5 2s 6d before the debt was due, and the plaintiff had accepted in full satisfaction for the debt.
The case reports the judgment as follows.
|“||payment of a lesser sum on the day in satisfaction of a greater, cannot be any satisfaction for the whole, because it appears to the Judges that by no possibility, a lesser sum can be a satisfaction to the plaintiff for a greater sum: but the gift of a horse, hawk, or robe, etc. in satisfaction is good. For it shall be intended that a horse, hawk, or robe, &c. might be more beneficial to the plaintiff than the money.
... he did not plead that he had paid the 5l. 2s. 2d. in full satisfaction (as by the law he ought) but pleaded the payment of part generally; and that the plaintiff accepted it in full satisfaction. And always the manner of the tender and of the payment shall be directed by him who made the tender or payment, and not by him who accepts it. And for this cause judgment was given for the plaintiff.