Pre-existing duty CASES
In English contract law, a pre-existing duty refers to obligations a party is already legally bound to perform, which generally cannot serve as valid consideration for a new promise.
Definition and Principles
Under traditional rules, performing or promising to perform an existing duty – either contractual or statutory – doesn’t usually constitute valid consideration unless the obligation significantly changes or provides additional benefit.
Common Examples
- Promises to pay more for the same contractual performance (often unenforceable).
- Public servants promising performance of duties already legally owed.
- Contracts where duties are expanded or significantly modified.
Legal Implications
- Promises based solely on pre-existing duties typically unenforceable.
- Additional consideration or practical benefit required to validate new promises.
Practical Importance
Understanding pre-existing duties prevents ineffective agreements, clarifies obligations, and guides parties in negotiating enforceable contract modifications.
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An unmarried father promised to pay the mother £1 per week to care for their child, provided she ensured the child was 'well looked after and happy'. The court held this promise was enforceable as it exceeded her existing statutory duty, constituting good consideration. Facts The claimant (the mother) and the defendant (the father) were an unmarried couple who had a child together. After they separated, the father paid for the child to live with a neighbour. The mother subsequently requested to have the child live with her. The father agreed and wrote to her, stating: ‘I am prepared to
Following the desertion of two sailors, a ship's captain promised the remaining crew extra wages to sail home. This promise was held unenforceable as the crew were already contractually bound to cover all emergencies, establishing that performing a pre-existing duty lacks consideration. Facts The plaintiff, Stilk, was a seaman on a voyage from London to the Baltic and back. He signed ship’s articles agreeing to be paid wages of £5 per month. The ship originally had a crew of eleven. During the voyage, two of the seamen deserted. The captain, Myrick, was unable to find replacements and, to prevent further
Plaintiffs, already contracted to deliver coal to a third party's order, delivered it to the defendant. The court held this delivery was good consideration for the defendant's separate promise to unload it, establishing that performance of an existing duty owed to a third party is valid consideration. Facts The plaintiffs (Scotson and others) were the owners of the ship ‘John’ and were under a contractual duty to a third party, X, to carry a cargo of coals and deliver them to the order of X. X sold this cargo of coals to the defendant, Pegg, and directed the plaintiffs to
A customer stopped a cheque used to buy bills from a seller who then failed. The seller's bank, to whom he was indebted, sued the customer. The court held the bank could recover, establishing that a pre-existing debt constitutes valid consideration. Facts Mr Misa sold four bills of exchange to Lizardi & Co., a firm with a strong credit history. Payment was to be made a few days later on the ‘mail day’. Misa duly drew a cheque on his bankers, Messrs. Currie & Co. (the plaintiffs), in favour of Lizardi. At the time, Lizardi was substantially in debt to
A witness, Collins, was subpoenaed by Godefroy and promised payment for attending court. Collins sued for non-payment. The court held that performing a pre-existing public duty (attending court under a subpoena) is not valid consideration for a new promise. Facts The claimant, Collins, an attorney, was subpoenaed to attend a trial and give evidence on behalf of the defendant, Godefroy. Collins attended the court for six days as required by the subpoena but was ultimately not called to testify. Collins brought an action in assumpsit, alleging that Godefroy had promised to pay him one guinea per day as remuneration for
