Consideration is what makes a bargain enforceable. A moral obligation is not enough: in Eastwood v Kenyon (1840) 11 A & E 438 Persuasive (Eng) a guardian who had spent money educating his ward could not enforce her later promise to repay him. Where there is truly no consideration, a promise contained in a properly executed deed still binds. For an individual, the seal is no longer required (Land and Conveyancing Law Reform Act 2009, s.64): the deed must instead be signed (or the signature acknowledged) before a witness who attests it, and delivered. This route is little used.
The four rules of consideration
1. It must move from the promisee
Only a person who has given consideration can enforce a promise. In Tweddle v Atkinson (1861) 1 B & S 393 Persuasive (Eng) a husband could not enforce two fathers' mutual promises to pay him, because he had given nothing. The Irish authority is McCoubray v Thompson (1868) 2 Ir CL 226 Binding (IE): where G transferred a farm on the defendant's promise to pay the plaintiff, the plaintiff could not sue — consideration had moved from G, not from him. (This is close to, but distinct from, privity — see Module 8 on third-party rights.)
2. It must not be past
If a promise is made after the act relied on as consideration, and the act was not part of the bargain, the consideration is past — and past consideration is no consideration (Roscorla v Thomas (1842) 3 QB 234 Persuasive (Eng)). Irish courts apply the same rule (Provincial Bank of Ireland v Donnell (1932) 67 ILTR 142 Binding (IE); Law Society of Ireland v O'Malley [1999] 1 IR 162 Binding (IE)). There is a limited exception (the rule in Lampleigh v Braithwait (1615) Hobart 105, restated in Pao On v Lau Yiu Long [1980] AC 614) where the past act was done at the promisor's request and payment was always understood.
3. It need not be adequate
The courts do not measure whether the exchange is fair; consideration must have some value, but adequacy is irrelevant. As Charleton J put it in ICS Building Society v Grant [2010] IEHC 17 Binding (IE), the law does not enquire into the adequacy of consideration. Even hidden value counts: chocolate-bar wrappers were part of the consideration in Chappell v Nestlé [1960] AC 87 Persuasive (Eng).
4. It must be sufficient
Though it need not be adequate, consideration must be sufficient — something the law recognises as valuable, even if it is not economically equivalent to what is given for it. A promise merely to refrain from complaining is not sufficient (White v Bluett (1853) 23 LJ Ex 36 Persuasive (Eng)), and consideration must not be illusory or a sham (Revenue Commissioners v Moroney [1972] IR 372 Binding (IE)). Performing an existing duty is generally not consideration (Stilk v Myrick (1809) 2 Camp 317 Persuasive (Eng)) — but doing more, or conferring a practical benefit, can be (Williams v Roffey Bros [1990] 1 All ER 512 Persuasive (Eng); and, on a statutory duty exceeded, McKerring v Minister for Agriculture [1989] ILRM 82 Binding (IE)). Genuinely giving up or compromising a legal claim is good consideration (Taylor v Smyth [1990] ILRM 377 Binding (IE)).
Part-payment of a debt
Paying part of a debt is generally not good consideration for a promise to forgo the balance — the creditor is owed the whole. The rule comes from Pinnel's Case (1602) 5 Co Rep 117a Persuasive (Eng) and was confirmed in Foakes v Beer (1884) 9 App Cas 605 Persuasive (Eng). There are recognised ways around it — for example, payment of a smaller sum early, in a different form, or by a third party (Welby v Drake (1825) 1 C & P 557 Persuasive (Eng)) — and the Irish courts have engaged with the rule (e.g. Corporation of Drogheda v Fairtlough (1858) 8 Ir CLR (ns) 98 Binding (IE)). Where the debtor cannot point to fresh consideration, the argument often shifts to promissory estoppel — but note that a concession squeezed out by pressure will not help (D & C Builders v Rees [1965] 3 All ER 837 Persuasive (Eng)).
The full, exam-ready version
Enforceability: consideration, promissory estoppel, intention and capacity — with the full case table, worked problems, a decision-tree and a model-answer skeleton.
see the full Contract course →Frequently asked questions
Does consideration have to be adequate?
No. It must have some value in the eyes of the law, but the courts do not weigh whether the exchange is a fair one (ICS Building Society v Grant; Chappell v Nestlé).
Is past consideration good consideration?
Generally no (Roscorla v Thomas). The narrow exception is where the past act was done at the promisor's request and payment was always understood (Lampleigh v Braithwait / Pao On).
Can paying part of a debt discharge the whole?
Not by itself (Foakes v Beer), unless there is fresh consideration (e.g. early payment, a different form, or third-party payment) or, on the facts, promissory estoppel prevents the creditor from claiming the balance.
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