Commercial Damages Quantification
Expert forensic accounting insight from Jack Ross Chartered Accountants
When a commercial dispute reaches litigation, the financial quantum is often the most contested element. Solicitors need a forensic accountant who can put a number on the claim credibly, present a methodology that holds up under cross-examination, and produce an expert witness report that meets the court's requirements. We've been doing this work since 1948 - across contractual claims, partnership breakdowns, tortious interference, and warranty actions - and the central challenge is always the same: putting a defensible number on what the injured party has lost.
What Are Commercial Damages?
Commercial damages are the monetary compensation a court awards to restore a party who has suffered financial loss because of another's wrongful conduct. The underlying principle is restitutio in integrum - putting the injured party back in the position they would have occupied had the wrong not occurred.
That sounds simple. In practice, it rarely is. The harm might stem from a single contractual breach with a clear loss period, or from a complex pattern of conduct spanning years. The amount at stake might be £50,000 or £50 million. Either way, the court needs a rigorous forensic accounting analysis that traces the causal link between the wrongful act and the financial consequences, separating genuine losses from commercial misfortune that would have happened regardless.
Types of Commercial Damages Claims
Breach of contract. The most common basis. A supplier fails to deliver, a distributor wrongfully terminates, a licensee stops paying royalties. The measure is the difference between the claimant's actual position and where they would have been had the contract been performed. Robinson v Harman [1848] established this expectation measure, and it remains the starting point for every contractual claim.
Tortious interference. Where a third party deliberately disrupts an existing contractual or business relationship, the injured party can recover resulting losses. These claims often involve complex causation questions because the harm flows from the interferer's actions rather than from a direct contractual counterpart. The expert must analyse and isolate the financial impact of the interference from other commercial factors affecting the business.
Breach of warranty. In M&A transactions, warranty claims arise when the seller's representations about the target business turn out to be wrong. Typical examples include overstated revenue, undisclosed liabilities, or inflated asset valuations. The work requires a comparison between the value of the business as warranted and its actual value - a task that sits squarely within a forensic accounting firm's expertise.
Partnership and shareholder disputes. When business relationships break down, the resulting litigation frequently involves competing claims. A minority shareholder alleging unfair prejudice under s994 Companies Act 2006 needs the loss established. A departing partner claiming they were undervalued on exit needs a forensic valuation of their interest. These cases demand both valuation skills and an understanding of the commercial dynamics that drove the breakdown.
How Commercial Damages Are Quantified
Three principal approaches drive the calculation, and the right methodology depends on the facts of the case.
The but-for test. This compares the injured party's actual financial position against where they would have been but for the wrongful act. Building the counterfactual requires historical trend analysis, industry benchmarking, and careful judgement about what would realistically have happened. It's the standard approach for loss of profits claims and works well where there's a reasonable trading history to project from.
Expectation loss versus reliance loss. Expectation loss aims to give the injured party the benefit of the bargain - the profits they expected to earn. Reliance loss instead recovers the expenditure wasted in reliance on the contract. The choice matters. A start-up with no trading history may struggle to prove expectation losses because projected profits are too speculative, but can recover the money it spent gearing up for a contract that was then breached. Anglia Television v Reed [1972] confirmed that reliance loss is available as an alternative measure where expected profits can't be reliably quantified.
Market value approach. Used primarily in warranty and misrepresentation claims, this compares the value of what was received against the value of what was promised. If a buyer paid £10 million for a business warranted to have EBITDA of £2 million, but actual EBITDA turns out to be £1.2 million, the loss is the overpayment calculated by applying an appropriate multiple to the shortfall.
Why Instruct a Forensic Accountant for Commercial Damages
Solicitors handle the law. But the amount at stake in a commercial claim is a financial question, and getting it wrong - either overstating or understating the loss - has real consequences. Overstate, and credibility with the court evaporates. Understate, and your client leaves money on the table at settlement or trial.
A forensic accountant brings three things to a dispute. First, the technical ability to build financial models, work through complex data sets, and calculate losses in a way that's both accurate and defensible. Second, independence - the expert's duty is to the court, not to the instructing party, and that independence is what gives the figure its weight. And third, experience of the litigation process itself: understanding what judges find persuasive, what opposing experts will challenge, and how to present financial evidence clearly.
Early instruction matters. We've seen too many cases where the expert is brought in after proceedings have been issued and the figures have already been pleaded based on rough calculations. By that point, the legal team is locked into a position that may not survive proper analysis. Instructing early - even before the letter of claim - gives the solicitor a realistic view of the claim's value and helps shape the dispute resolution strategy around a credible number.
Expert Evidence in Commercial Disputes
CPR Part 35 and Practice Direction 35 govern expert evidence in civil proceedings. The expert's report must set out the facts and assumptions relied upon, the methodology used, the calculations performed, and the conclusions reached. Every step must be transparent enough for the opposing expert to test it.
In many cases, the court directs expert discussions under CPR Part 35.12. The two experts meet, compare their analyses, and produce a joint statement identifying areas of agreement and disagreement. These discussions often narrow the issues dramatically. A claim with a £5 million gap between the parties' positions might come down to two or three specific disagreements worth £800,000 in total - and the court can then focus its attention on those points.
Hot-tubbing (concurrent expert evidence) is increasingly common in the Business and Property Courts. Instead of each expert giving evidence separately, both are questioned together, allowing the judge to probe the differences directly. This format favours experts who can explain their methodology clearly and concede reasonable points without undermining their overall opinion. It exposes weak analysis quickly.
Our Approach
We work on these claims in four stages. Scoping: we review the available material, identify the key financial issues, and agree the scope of work with the instructing solicitor. Analysis: we collect and work through the financial data, build the model, and stress-test the assumptions. Reporting: we prepare a CPR Part 35-compliant expert report setting out our opinion on quantum, together with supporting schedules and appendices. Court: where the case doesn't settle, we give oral evidence, participate in expert discussions, and, where directed, give concurrent evidence alongside the opposing expert.
We're comfortable acting as a single joint expert where the court directs it, or as a party-appointed expert. Either way, the duty is to the court, the analysis is independent, and the opinion is ours.
Key Takeaways
- Commercial damages claims require an expert who can build a defensible counterfactual and withstand cross-examination on methodology
- The but-for test, expectation/reliance loss, and market value approach are the three principal quantification methods - the right choice depends on the facts
- Early instruction gives solicitors a realistic figure before the claim is pleaded, avoiding credibility problems later
- Expert discussions under CPR Part 35.12 regularly narrow the issues, often reducing the gap between the parties by 80% or more
- We handle the full lifecycle: scoping, analysis, reporting, and oral evidence including hot-tubbing in the Business and Property Courts
To discuss a commercial damages instruction, contact Jack Ross or call 0161 832 4451. We provide preliminary quantum assessments to help solicitors evaluate the viability of a claim before committing to full litigation support.
Frequently Asked Questions
We work across breach of contract, tortious interference, breach of warranty, ownership actions, partnership breakdowns, and professional negligence. The common thread is that each case turns on a financial question - how much has the injured party lost - and that question needs rigorous analysis to answer properly.
We select the methodology that fits the claim. For lost profits, we apply the but-for test, building a counterfactual from historical trading data and industry benchmarks. For warranty claims, we compare the value of what was promised against what was delivered. For wasted expenditure claims, we total the costs incurred in reliance on the contract. Each calculation is documented in sufficient detail for the opposing expert to test every assumption.
As early as possible - ideally before the letter of claim. Early instruction means the figures in the claim are based on proper analysis rather than rough estimates. It also helps identify disclosure requirements early, gives the solicitor a realistic view of the claim's value for settlement and dispute resolution purposes, and avoids the credibility problem of having to revise the pleaded figure downwards once the detailed work is done.
Yes. Where the court directs the appointment of a single joint expert under CPR Part 35.7, we act in that capacity regularly. The role requires particular care because the expert's opinion is the only financial evidence the court receives. We ensure both parties have equal opportunity to provide information and raise questions, and the report addresses the issues identified by both sides.
Fees depend on the complexity of the case, the volume of financial data, and the number of issues in scope. A straightforward breach of contract claim with clean records might cost £8,000 to £15,000 for the full report. Multi-party cases with complex financial modelling, multiple loss periods, or contested valuations can be significantly more. We provide a fee estimate after reviewing the initial papers and scoping the work with the instructing solicitor.