The case law on performance and breach is rich and fact-sensitive. The cases below form the doctrinal spine of this topic and are essential for tutorials and examination.
Cutter v Powell established the entire obligation rule in its starkest form. The seaman's widow could not recover for partial performance of an entire contract; the contractual allocation of risk was upheld. The case remains controversial for its perceived harshness, but it reflects the principle that parties should be held to their bargains. Modern employment law has moved far from Cutter, but the entire obligation rule survives in construction and service contracts.
Hochster v De la Tour introduced the doctrine of anticipatory breach. The courier could sue immediately on the employer's renunciation in May, without waiting until 1 June. The decision promoted commercial efficiency by allowing the innocent party to mitigate loss and re-enter the market promptly. It also confirmed that a contract could be breached before performance was due. The case provoked academic debate: how could a contract be breached before the obligation arose? The answer lies in the reciprocal nature of contractual obligations and the concept of renunciation as a distinct wrong.
Hoenig v Isaacs and Bolton v Mahadeva define the boundaries of substantial performance. The former permitted recovery for work nearly complete with minor defects; the latter denied it where defects were significant. The cases turn on matters of degree, making them difficult to apply predictably. They illustrate the tension between holding contractors to their obligations and preventing unjust enrichment of the employer who retains the benefit.
Hong Kong Fir Shipping established the innominate (intermediate) term, under which the remedy depends on the consequences of breach rather than the label attached to the term. The shipowner's breach of the seaworthiness obligation delayed the vessel and reduced its earning capacity, but the delay was not so severe as to deprive the charterer of substantially the whole benefit of the five-year charter. Diplock LJ's judgment is a landmark of functionalist reasoning, preferring substance over form. It has been criticised for reducing certainty, but it remains orthodox.
White & Carter (Councils) Ltd v McGregor is the most controversial case in this area. The House of Lords held (by a bare 3–2 majority) that an advertising contractor who affirmed a repudiated contract could continue to display advertisements and claim the full price, despite the customer's repudiation. Lord Reid's limitation—that the claimant must have a legitimate interest in performing rather than claiming damages, and must not require the defendant's cooperation—has been invoked in later cases to confine White & Carter. The decision challenges the normal rule that the innocent party's duty is to mitigate. It has been distinguished more often than followed.
The Mihalis Angelos [1971] 1 QB 164 concerned a charterparty requiring the vessel to be 'expected ready to load' by 1 July. The charterers repudiated on 17 July. The owners accepted the repudiation. It emerged that the vessel could not in fact have been ready by 1 July, so the owners would themselves have been in breach. The Court of Appeal held that the charterers' repudiation discharged the contract immediately, and the owners' prospective breach was irrelevant. The case clarifies that acceptance of an anticipatory breach crystallises discharge at that moment, regardless of hypothetical future events.
Charles Rickards Ltd v Oppenheim demonstrates how time can be made of the essence by notice. The contract for a Rolls-Royce body did not make time of the essence. After repeated delays, the buyer gave notice requiring delivery in four weeks. The seller failed to deliver. The Court of Appeal held that the buyer was entitled to terminate. The case illustrates the balance between initial flexibility and the innocent party's ultimate entitlement to finality.
Sumpter v Hedges shows that no restitutionary recovery is available where the innocent party has no real choice about accepting the benefit. A builder who abandoned a half-built structure on the defendant's land could not recover on a quantum meruit for the value of the work; the landowner had no option but to accept it. The case confines substantial performance and unjust enrichment doctrines by requiring the innocent party's genuine acceptance of partial performance.