Remoteness and mitigation

This topic completes the damages sequence. Week 13 asked what interest damages protect: expectation, reliance, loss of amenity, cost of cure, and the limits imposed by compensation. Week 14 asks a different question: even if the claimant has suffered a loss caused by breach, is that loss too remote, or should it have been avoided? Remoteness and mitigation are not minor appendices to the law of damages. They are the mechanisms by which English law prevents the expectation measure from becoming a general insurance against every misfortune following breach.

Remoteness is concerned with the type of loss for which the defendant has undertaken legal responsibility. The orthodox rule is still derived from Hadley v Baxendale: recoverable losses are those arising naturally, according to the usual course of things, or those within the parties' reasonable contemplation because special circumstances were communicated at the time of contracting. The modern formula, especially after The Heron II, is not bare foreseeability. It requires a serious possibility or real danger of loss, judged at contract formation, and by reference to the knowledge then reasonably available to the contract-breaker. The question is not whether this precise loss in this precise amount was predicted. It is whether the relevant kind of loss was sufficiently within contemplation.

Mitigation operates later. It is not, strictly, a duty owed to the contract-breaker. The claimant commits no wrong by failing to mitigate. Rather, the claimant cannot recover loss which reasonable steps would have avoided; may recover the reasonable cost of reasonable mitigating steps, even if unsuccessful; and must generally give credit for benefits obtained by mitigation. The inquiry is practical, fact-sensitive and generous to the innocent party. A claimant is not required to gamble, litigate against third parties, ruin its commercial reputation, or accept humiliating terms merely to reduce the defendant's liability.

For Cambridge purposes, the central difficulty is to keep the doctrines distinct while recognising their functional overlap. Remoteness limits the scope of recoverable loss ex ante, by reference to contemplation and allocation of risk at contract formation. Mitigation limits damages ex post, by reference to the claimant's reasonable response after breach. Both doctrines reflect a deeper idea: contract damages compensate for legally attributable loss, not for every factual consequence of non-performance.

The law of remoteness in contract begins with a railway delay and a broken mill shaft. In Hadley v Baxendale the claimant millers could not recover lost profits arising from the mill being stopped while a carrier delayed delivery of the broken shaft to engineers. The carrier did not know that the mill had no spare shaft and would remain idle. The Exchequer therefore articulated the familiar two-limb rule: losses recoverable as arising in the usual course of things, and losses recoverable because special circumstances were known to both parties at the time of contract. The case is often presented as a simple foreseeability decision. It is better understood as a rule about the informational basis on which contractual risk is priced and assumed.

Nineteenth-century contract law was concerned with commercial certainty. Carriers, sellers and suppliers needed to know the risks for which they were bargaining. Hadley is therefore not a tort rule transplanted into contract. Tort typically asks what harm was reasonably foreseeable at the time of the wrong. Contract asks what loss the promisor can reasonably be taken to have contemplated at the time of undertaking the obligation. That temporal difference is fundamental. The promisor prices the contract before breach; the law is cautious about imposing liability for abnormal consequences unless the relevant facts were disclosed.

The twentieth century refined the probability threshold. In Victoria Laundry, the Court of Appeal allowed recovery for ordinary lost laundry profits caused by delayed delivery of a boiler, but denied exceptionally lucrative dyeing contracts because these were not made known. The decision emphasised degrees of knowledge and distinguished ordinary business profits from extraordinary opportunities. The Heron II then rejected the idea that tortious foreseeability and contractual remoteness are identical. A loss need not be more likely than not; but it must be a real danger or serious possibility contemplated as not unlikely in the contractual setting.

The late twentieth and early twenty-first centuries introduced a further complication: assumption of responsibility. In The Achilleas the House of Lords held that a shipowner could not recover the full loss flowing from a follow-on charter lost because of late redelivery. Although such loss was, in one sense, foreseeable, the majority reasoned that the market understanding of time charterparties confined liability to the difference between market and charter rates during the overrun period. The case unsettled the apparent simplicity of Hadley. Does it create a new test, asking whether the defendant assumed responsibility for the loss? Or is assumption of responsibility merely the underlying explanation of Hadley, relevant only in exceptional cases where market practice shows that reasonable contemplation would over-extend liability?

Mitigation developed alongside, but differently. Its leading expression is British Westinghouse, where the claimant bought replacement turbines after the defendants supplied inefficient ones. The new turbines were more efficient than the contract goods, and the benefit had to be brought into account. The law thereby avoided overcompensation. Subsequent cases such as Payzu v Saunders added that an innocent buyer may sometimes be required to accept a renewed offer from the contract-breaker if doing so is commercially reasonable. But the doctrine remains protective of the claimant. Its premise is not moral censure of the innocent party, but the compensatory principle: the defendant should pay for loss caused by breach, not for avoidable loss unreasonably allowed to accumulate.

1. Causation is prior, but not sufficient. A claimant must first show that the breach caused the loss in fact and law. Remoteness then asks whether the loss, though caused by breach, is too distant a consequence to be recoverable. Mitigation asks whether subsequent loss should be treated as attributable to the claimant's unreasonable inaction rather than to the defendant's breach.

1. The Hadley rule remains the starting point. Losses are recoverable if they fall within either limb. The first limb covers losses arising naturally, according to the usual course of things. These are ordinary consequences of breach, requiring no special communication. The second limb covers losses arising from special circumstances known to both parties when the contract was made. It is not enough that the claimant knew of those circumstances; the defendant must have had sufficient knowledge to appreciate the relevant risk.

1. The relevant knowledge is assessed at formation, not breach. This distinguishes contract from tort and supports the bargain-based character of contractual liability. A defendant may become aware before breach that serious loss will result, but the orthodox remoteness inquiry asks whether that loss was within contemplation when the contractual obligation was undertaken. Later knowledge may matter to waiver, variation, estoppel, repudiation, or mitigation, but it does not ordinarily expand the original scope of contractual responsibility.

1. The threshold is higher than mere tortious foreseeability. The Heron II established that a loss need not be probable in the sense of more likely than not. However, it must be a serious possibility, real danger, or not unlikely result of breach. The precise verbal formula varies across the speeches, but the point is stable: contract remoteness requires a more substantial degree of contemplation than the thin foreseeability sufficient in negligence.

1. The law focuses on the kind or type of loss, not its precise extent. If the relevant kind of loss is within contemplation, the claimant is not usually barred because the actual amount is greater than expected. Conversely, a large but ordinary loss may be recoverable, while a qualitatively different special loss may be too remote. The difficulty lies in defining the type of loss at the right level of abstraction. In Victoria Laundry ordinary loss of laundry profits was recoverable; exceptional dyeing profits were not. In Parsons, illness among pigs caused by defective feed storage was within the type of physical harm contemplated, even if the severity was unusual.

The doctrinal spine begins with Hadley v Baxendale. Its enduring importance lies not merely in the two-limb formula, but in the commercial policy behind that formula. If an ordinary carrier is not told that a mill will stop until a shaft is returned, it cannot price or insure the risk of lost profits. The first limb deals with ordinary consequences; the second with communicated special circumstances. Both limbs are objective, but the second depends upon the defendant's knowledge.

Victoria Laundry refined the rule by showing that knowledge can operate at different levels of generality. A seller of a boiler knew that a laundry business wanted the boiler for business use. It was therefore liable for ordinary lost profits caused by delay. It was not liable for extraordinary profits from particularly lucrative dyeing contracts not communicated to it. This is an indispensable case for the distinction between type and extent of loss.

The Heron II corrected any tendency to assimilate contract remoteness to tort foreseeability. A late ship carrying sugar reached Basra after the sugar market had fallen. The owners knew sugar was a market commodity and that delay might expose the charterer to market movement. The loss was recoverable. But the House of Lords insisted that contract requires more than a bare possibility. The various formulations, such as serious possibility and real danger, remain important because they express the higher contractual threshold.

Parsons demonstrates that the court may frame the relevant type of loss broadly where physical damage is in issue. A defective hopper caused pig food to become mouldy, resulting in diseased pigs. The supplier argued that the particular disease was unforeseeable. The Court of Appeal held the loss recoverable: illness among pigs from bad feed storage was within the contemplated kind of harm. The case is useful for problem questions because defendants often define the loss too narrowly.

The Achilleas is the modern problem case. Late redelivery of a vessel caused the owners to lose a profitable follow-on charter after market rates fell. On orthodox Hadley reasoning, market loss from late redelivery may look foreseeable. Yet the House of Lords restricted recovery to the market rate for the overrun period, relying on the commercial understanding of the shipping market and the risk the charterer could reasonably be taken to have assumed. The safest view is that the case supplements rather than replaces Hadley.

Supershield illustrates the post-Achilleas tendency to treat assumption of responsibility as an explanatory principle, not a universal new test. A flood caused by a defective valve and a blocked drain was recoverable despite the combination of events. The Court of Appeal emphasised that Hadley generally works by identifying the losses for which responsibility is assumed. The case is a good antidote to overusing The Achilleas.

British Westinghouse remains the leading mitigation case. Replacement turbines, bought because the original turbines were inefficient, proved more efficient and produced benefits. Those benefits reduced the recoverable damages. The decision supplies the core propositions: the claimant must act reasonably, reasonable mitigation expenses are recoverable, and compensating damages must account for benefits sufficiently connected with mitigation.

Payzu v Saunders is the sharpest example of mitigation requiring a claimant to deal again with the contract-breaker. The seller refused to deliver except for cash in advance, contrary to the original credit terms. The buyer declined and allowed losses to grow. The Court of Appeal held that it should have accepted the offer and claimed any remaining loss. The case should be used cautiously. It does not require a claimant to submit to oppressive terms; it shows that reasonableness may require commercially sensible acceptance of substitute performance.

See practice questions section below.

See further reading section below.