## **Learning Outcomes**

This article explains the duty to mitigate in contract law as tested in SQE1, including:

- when the duty arises after breach, who it binds, and how it limits recoverable damages
- what amounts to reasonable mitigation steps in sales, services, employment, and shipping contracts
- how courts assess the burden of proof on the defendant and the type of evidence that demonstrates a failure to mitigate
- how mitigation interacts with the measure of damages, market-based “cover” purchases or resales, and the crediting of gains
- the relationship between mitigation, causation, remoteness, affirmation and contributory negligence, and how to distinguish these concepts in SQE1 problem questions
- typical factual patterns where mitigation is in issue, including anticipatory breach, refusal of substitute performance, and decisions that increase loss but remain reasonable
- exam-focused strategies for identifying mitigation arguments for both claimant and defendant, structuring clear analysis, and avoiding common pitfalls in realistic SQE1 multiple-choice and written scenarios.

## **SQE1 Syllabus**

For SQE1, you are required to understand the duty to mitigate as it applies to contractual discharge and remedies, with a focus on the following syllabus points:

- the principle that a non-breaching party must take reasonable steps to reduce losses after a breach
- how mitigation affects the calculation of damages
- the limits of the duty to mitigate and who bears the burden of proof
- the relationship between mitigation, causation, and remoteness
- the distinction between mitigation and contributory negligence in contract law
- the market measure approach and “cover” purchases or resales in sales contracts
- when a claimant may have to accept reasonable substitute performance offered post-breach
- crediting gains obtained through reasonable mitigation against the damages claimed
- the impact of anticipatory breach, affirmation and timing on mitigation

## **Test Your Knowledge**

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision._

1. What is the duty to mitigate, and when does it arise in contract law?
2. If a seller breaches a contract for goods, what is the buyer expected to do to mitigate loss?
3. Who bears the burden of proving a failure to mitigate, and what must they show?
4. How does the duty to mitigate differ from contributory negligence in contract law?

## **Introduction**

The duty to mitigate is a fundamental rule in contract law that limits the damages recoverable by a party following a breach. It requires the non-breaching party to take reasonable steps to reduce their losses, rather than allowing avoidable harm to accumulate and then claiming full compensation. This principle ensures that damages reflect only actual, unavoidable loss and prevents claimants from recovering for losses they could have reasonably prevented. Reasonableness is judged objectively: the law asks what a prudent person would have done in the circumstances, not whether the claimant could have achieved a perfect outcome in hindsight.

## The Duty to Mitigate: Principle and Scope

When a contract is breached, the innocent party is not entitled to sit back and allow losses to mount. Instead, they must act as a reasonable person would in the circumstances to reduce the impact of the breach. This may involve seeking substitute goods on the market, arranging alternative transport or accommodation, pursuing replacement suppliers or customers, or seeking comparable employment. In sales cases, this often means a “cover” purchase (by the buyer) or a reasonable resale (by the seller). In services and projects, it may mean redeploying resources, sub-contracting, or re-letting capacity to new customers.

> **Key Term: duty to mitigate**
> The obligation on a non-breaching party to take reasonable steps to reduce losses resulting from a breach of contract. Losses that could have been avoided by reasonable action are not recoverable as damages.

The duty to mitigate is not absolute. The innocent party is not required to take extraordinary risks, incur unreasonable expense, or sacrifice their own commercial interests. The law recognises a range of reasonable options and does not penalise a claimant for choosing one reasonable course over another. The standard is what a reasonable person would do in similar circumstances, with regard to timing, cost, risk and practicality.

> **Key Term: reasonable steps**
> Actions that a prudent person would take in the circumstances to limit loss after a breach, judged objectively.

Mitigation is a live issue in many contexts:

- sales contracts (buyers “cover” and sellers resell within a reasonable time; statutory market measures under the Sale of Goods Act complement the duty to mitigate)
- employment (wrongful dismissal: the employee is expected to seek comparable work within a reasonable period)
- charters and logistics (obtaining substitute carriage, storage or routes)
- services and construction (sourcing alternative sub-contractors, resequencing work or engaging temporary resource to avoid delay losses)

## How Mitigation Affects Damages

Damages in contract law aim to put the claimant in the position they would have been in had the contract been performed. However, losses that could have been avoided by reasonable mitigation are excluded from recovery. This operates in two directions.

First, failure to mitigate reduces damages. If the claimant declines a reasonable opportunity to avoid or reduce loss, the court will limit recovery to the loss that would have been suffered had reasonable steps been taken. For example, if a buyer could have sourced substitute goods at a modestly higher price, but instead claimed the full consequential losses from halting production, damages will be limited to the reasonable “buy-in” price difference and related unavoidable costs.

Second, reasonable mitigation can generate benefits. Those gains must be credited against the damages claimed, but only where they arise from the steps taken to mitigate the breach (not from independent, collateral transactions). For instance, if a claimant replaces defective equipment and the replacement yields efficiency savings which a prudent person would have sought to avoid continuing losses, those savings may be set against the damages claimed for the original breach.

Damages will be assessed on the facts at the time mitigation decisions were made, using the information reasonably available then. The law does not require perfection: only reasonableness.

The burden of proving a failure to mitigate rests with the party in breach, who must show both that reasonable steps were available and that the claimant failed to take them.

> **Key Term: burden of proof (mitigation)**
> The responsibility of the breaching party to demonstrate that the claimant failed to take reasonable steps to mitigate loss.

Worked into the damages assessment are familiar market measures. In a liquid market, the usual measure is the difference between the contract price and the market price at the time the goods ought to have been delivered or accepted, assuming reasonable “cover” or resale. The statutory measures under the Sale of Goods Act reflect this approach but do not displace the duty to mitigate. Where there is no ready market, the claimant may take reasonable time to find a substitute or buyer, and the damages will reflect that reality.

Reasonable mitigation may increase loss. If steps that are reasonable (for example, a product recall to protect safety or reputation) increase the immediate loss, the additional costs can still be recovered. The test is practicability and proportionality, not whether the chosen path turned out to be most economical.

### **Worked Example 1.1**

A supplier fails to deliver raw materials to a manufacturer as agreed. The manufacturer can buy the same materials from another supplier at a slightly higher price. What is the manufacturer's duty?

> **Answer:** The manufacturer must take reasonable steps to source the materials elsewhere, even at a modestly higher price. Damages will be limited to the difference in cost, not the full loss of production if the manufacturer could have avoided it by buying substitute materials.

### **Worked Example 1.2**

An employee is wrongfully dismissed and chooses not to look for new work for several months. What is the effect on damages?

> **Answer:** The employee is expected to seek comparable employment to mitigate loss. If they fail to do so, damages for lost earnings may be reduced by the amount they could reasonably have earned in alternative employment.

### **Worked Example 1.3**

A buyer refuses to accept delivery of goods. The seller does not attempt to resell the goods and claims the full contract price as damages. Is this permitted?

> **Answer:** No. The seller must take reasonable steps to resell the goods to limit loss. Damages will be reduced by the amount the seller could have obtained from a reasonable resale.

### **Worked Example 1.4**

A supplier breaches a contract by insisting on cash on delivery instead of the original credit terms, but offers timely delivery at the original price on that basis. The buyer refuses and sues for non-delivery losses. How will the court approach mitigation?

> **Answer:** If accepting cash on delivery was a reasonable commercial solution to avoid greater loss (for example, securing the goods at the agreed price without undue hardship), the buyer’s refusal may be treated as a failure to mitigate. Damages may be limited to losses that would have occurred had the buyer accepted the reasonable substitute arrangement.

### **Worked Example 1.5**

A claimant replaces defective turbines with more efficient models to avoid continuing losses. The replacement improves overall performance beyond the original specification. Must these efficiency gains be credited?

> **Answer:** Yes, where the gains arise from reasonable steps taken in response to the breach (replacing defective equipment to avoid ongoing loss), benefits are credited against damages. The claimant cannot be put in a better position than performance would have provided.

## Relationship to Causation and Remoteness

Mitigation interacts with the principles of causation and remoteness. Only losses caused by the breach and within the reasonable contemplation of the parties are recoverable. If the claimant fails to mitigate, the chain of causation is broken for those avoidable losses: they are treated as arising from the claimant’s own decision, not the breach.

Remoteness is judged at the time of contracting: was the type of loss sufficiently likely to have been in the parties’ contemplation? If so, and the loss still could not reasonably be avoided at the time of breach, it is recoverable. If a loss is too remote, mitigation cannot convert it into a recoverable head of loss.

Mitigation is distinct from contributory negligence. In contract law, contributory negligence is generally not a defence unless the claim involves a breach of a contractual duty of care that overlaps with tort. Mitigation focuses on reasonable post-breach conduct; contributory negligence concerns pre-breach fault contributing to the occurrence of loss.

> **Key Term: contributory negligence (contract)**
> A partial defence reducing damages where the claimant's own negligence contributed to their loss, but only applies in contract where the breach is also a tort.

Mitigation also requires that gains from reasonable mitigating steps be accounted for. The crediting of gains is part of causation analysis: damages should reflect the net effect of the breach once reasonable countermeasures are taken.

## Practical Application of the Duty to Mitigate

The duty to mitigate applies in a wide range of contractual contexts, including sales of goods, employment contracts, charters, and service agreements. The innocent party must act promptly and reasonably, but is not required to accept inferior substitutes or unreasonable terms. The law expects commercial realism: accept practical alternatives where they are reasonable, reject proposals that impose undue risk or disadvantage.

Typical applications include:

- Buyers “cover” promptly at the best available price; sellers resell within a reasonable time to limit storage and depreciation costs.
- Service recipients source alternative providers or re-sequence work to reduce delay losses where practical.
- Employees dismissed unlawfully seek comparable roles rather than remaining wholly inactive; reasonable time to regroup is allowed.
- Charterers or shippers under transport contracts secure substitute vessels or routes where prudent and affordable.

Courts assess mitigation in the round: timing, market conditions, cashflow, risk and reputation are all relevant. A prudent course chosen in good faith will usually satisfy the duty to mitigate.

## Limits and Exceptions

The duty to mitigate does not require the innocent party to take steps that would expose them to unreasonable risk, significant expense, or reputational harm. They are not required to accept fundamentally different or inferior performance, nor to accept offers from the breaching party if it would be commercially unreasonable. A claimant is not bound to litigate against third parties to reduce loss where litigation is uncertain, complex or unduly burdensome.

Sometimes, however, accepting substitute performance from the breaching party is reasonable and expected. Where a departure from the original terms is minor and resolves the breach without imposing undue burden (such as a change to payment mechanics that is commercially acceptable), declining that solution can reduce recoverable damages. Conversely, where acceptance would strip the claimant of bargained-for protections, expose them to significant risk, or cause humiliation or reputational damage (for example, in employment), refusal is likely to be reasonable.

> **Key Term: unreasonable risk (mitigation)**
> A risk that a reasonable person would not accept in the circumstances when attempting to reduce loss after a breach.

The claimant is not required to take speculative or extraordinary steps. They need not adopt the cheapest possible solution if it would compromise legitimate commercial interests. The law acknowledges that a modest premium may be payable for speed, reliability or reputation where that is reasonable.

## Burden of Proof and Strategic Considerations

The party in breach must prove that the claimant failed to mitigate and that reasonable steps were available. They must show:

- a specific, practical measure the claimant could reasonably have taken (for example, a timely cover purchase at a particular market price), and
- that taking the measure would have reduced the loss.

Claimants should keep records showing the steps taken and the reasoning behind them: enquiries, market quotes, alternatives considered, and risk assessments. Decision-making contemporaneous with the breach is important: courts judge reasonableness using the information available at the time, not perfect hindsight.

Defendants should focus on clear, realistic alternatives and reliable market data. General assertions that the claimant “could have done more” rarely succeed unless supported by evidence of actual, accessible options.

### **Exam Warning**

> If a question asks about damages after breach, always consider whether the claimant could have taken reasonable steps to reduce loss. Failing to discuss mitigation may result in an incomplete answer.

## Mitigation and Affirmation

If the innocent party affirms the contract after an anticipatory breach, they are not required to mitigate by treating the contract as at an end, but must act reasonably once performance falls due. Affirmation preserves the contract and may limit damages to losses suffered after the date for performance. Courts may refuse to allow affirmation if it would be unreasonable or require the breaching party's cooperation in a way that is impractical. The timing matters: market movements between anticipatory repudiation and the performance date can affect the measure of loss, and reasonable steps (such as hedging, pre-booking substitutes or securing contingencies) may be expected in fast-moving markets.

Affirmation does not excuse all mitigation. Once the breach crystallises, the innocent party must still act reasonably to avoid escalating loss. If affirmation simply defers the inevitable, the court will look critically at avoidable losses suffered in the interim.

## **Key Point Checklist**

_This article has covered the following key knowledge points:_

- The duty to mitigate requires the non-breaching party to take reasonable steps to reduce losses after a breach.
- Losses that could have been avoided by reasonable mitigation are not recoverable as damages.
- The burden of proving a failure to mitigate lies with the party in breach.
- The duty to mitigate is limited to reasonable steps and does not require extraordinary action or risk.
- Mitigation interacts with causation and remoteness but is distinct from contributory negligence.
- Courts may reduce damages if the claimant fails to mitigate, but will not require acceptance of inferior or risky alternatives.
- Benefits reasonably obtained through mitigation must be credited against damages.
- In sales and services, prompt “cover” purchases or resales are a common and expected mitigation measure.
- Affirmation after anticipatory breach affects timing and measure of loss, but mitigation obligations still arise when performance is due.

## **Key Terms and Concepts**

- duty to mitigate
- reasonable steps
- burden of proof (mitigation)
- contributory negligence (contract)
- unreasonable risk (mitigation)

Discharge of contract and remedies - Duty to mitigate