--- title: "Negligent Due Diligence: When You Can Claim" url: https://professionalnegligenceclaimsolicitors.co.uk/negligent-due-diligence-when-you-can-claim/ date: 2026-09-03 modified: 2026-09-03 lang: en author: "Qasim Mehmood" description: "Buying a business based on negligent professional advice can result in substantial financial losses. Find out when negligent due diligence may give rise to a professional negligence claim, who may be liable and what compensation could be recovered." categories: - "Case study" - "Cases" - "Contracts" - "conveyancer" - "Court of Appeal" - "CPR" - "Lawyers" - "legal" - "Legal Negligence" - "Letter Before Action" - "Letter Before Claim" - "LEXLAW" - "Limitation periods" - "Litigation advice" - "Media" - "negligence" - "Negligence Claim" - "Negligent Solicitor" - "Negligent Valuation" - "News" - "Pre Action Protocols" - "professional negligence" - "Professional Negligence Cases" - "Supreme Court" - "Surveyor Negligence" tags: - "accountant negligence" - "business acquisition" - "business dispute" - "business losses" - "business purchase" - "business valuation" - "compensation claim" - "due diligence claims" - "due diligence failure" - "financial loss" - "hidden liabilities" - "legal advice" - "lexlaw" - "negligence claims" - "negligent advice" - "negligent due diligence" - "professional advisers" - "Professional negligence" - "solicitor negligence" image: https://professionalnegligenceclaimsolicitors.co.uk/wp-content/uploads/Negligent-Due-Diligence-When-You-Can-Claim-1024x683.png word_count: 1648 --- # Negligent Due Diligence: When You Can Claim Buying a business is one of the largest financial commitments many individuals and companies will ever make, and due diligence exists precisely to protect that decision. Purchasers rely on [accountants](https://professionalnegligenceclaimsolicitors.co.uk/compensation-negligent-accountants-financial-tax-advisors/), [solicitors](https://professionalnegligenceclaimsolicitors.co.uk/sue-negligent-solicitor-law-firm/), tax advisers and corporate finance specialists to look beneath the surface of a target company, to verify its accounts, uncover hidden liabilities, check title to key assets, and flag any looming insolvency or litigation risk before contracts are signed. When that exercise is carried out incompetently, and a buyer completes a purchase it would never have agreed to on properly conducted diligence, the fallout can be severe, ranging from a business worth a fraction of the price paid to inherited debts, undisclosed tax exposure, or a company that collapses within months of completion. In these circumstances, a [professional negligence claim](https://professionalnegligenceclaimsolicitors.co.uk/professional-negligence-claims/) against the adviser responsible may provide a genuine route to recovery. This article explains when negligent due diligence becomes legally actionable, who can be sued, what a claimant must prove, and the compensation and time limits that apply ## What Due Diligence Is Meant to Achieve Due diligence on a business acquisition is rarely the work of a single adviser. [Accountants](https://professionalnegligenceclaimsolicitors.co.uk/compensation-negligent-accountants-financial-tax-advisors/) examine the target's financial statements, normalise earnings, and test whether reported profitability is sustainable. [Solicitors](https://professionalnegligenceclaimsolicitors.co.uk/sue-negligent-solicitor-law-firm/) review title to shares and assets, material contracts, employment liabilities, pending or threatened litigation, and regulatory compliance. Tax advisers investigate historic exposures and outstanding [HMRC enquiries](https://lexlaw.co.uk/hmrc-tax-dispute-lawyers/), while corporate finance advisers draw the findings together to inform price, structure, and the warranties and indemnities negotiated in the sale agreement. Each workstream carries its own professional duty, and a failure in any one of them can expose the buyer to loss that a competently conducted exercise would have prevented. ### Want legal advice on the merits of your case? Your legal enquiry goes immediately to our PN litigation team in Middle Temple, London. We can't take on low value cases or give free legal advice - our minimum fee is £1750 +VAT for a conference with a solicitor and barrister. Call us on +442071830529. [Check My Case Now ✔](https://professionalnegligenceclaimsolicitors.co.uk/litigation-case-assessment-form/) ## When Does Due Diligence Become Negligent? The law does not judge an adviser's work with the benefit of hindsight. A due diligence exercise is not negligent simply because the business subsequently underperformed, or because a risk that later materialised was not identified at the time. The governing principle, rooted in [Hedley Byrne & Co Ltd v Heller & Partners Ltd [1964] AC 465](https://www.lawteacher.net/cases/hedley-byrne-v-heller.php), is that a professional who assumes responsibility for advice owes a duty to exercise reasonable skill and care, and the test is whether the adviser fell below the standard of a reasonably competent practitioner in the same field, judged on the information reasonably available at the time. A report that proves optimistic with hindsight will not found a claim. A report that overlooked material information sitting in the data room, accepted management figures without proper verification, or fell short of the scope actually instructed, may well do so. ## Common Examples of Negligent Due Diligence Negligence in a due diligence exercise tends to recur in recognisable patterns: - Accepting management accounts and forecasts at face value without independent testing against underlying records. - Failing to identify contingent liabilities or pending litigation discoverable within the data room. - Overlooking unresolved tax exposures or HMRC enquiries that later crystallise into significant liabilities for the new owner, an issue frequently addressed by our colleagues at [taxdisputes.co.uk](https://taxdisputes.co.uk/) once completion has taken place. - Missing signs of balance sheet insolvency or serious cash flow distress, leaving a buyer to discover the target is barely solvent only once creditors begin pressing for payment. - Failing to verify title to key assets or intellectual property central to the business's trade. - Inadequate scrutiny of related-party transactions or one-off income wrongly treated as recurring. ## Establishing Liability: What a Claimant Must Prove Where the adviser was formally engaged by the buyer, a duty of care arises both under the retainer and concurrently in tort, following Henderson v Merrett Syndicates Ltd [1995] 2 AC 145. More difficult questions arise where a due diligence report was prepared for one party, typically the seller in a vendor due diligence exercise, but relied upon by another. Following [Caparo Industries plc v Dickman [1990] 2 AC 605](https://professionalnegligenceclaimsolicitors.co.uk/breach-of-duty-key-tort-law-judgment-caparo-dickman/), a duty to a third party will generally only arise where the adviser knew the report would be provided to, and relied upon by, a specific person for a specific transactional purpose, as in [JEB Fasteners Ltd v Marks Bloom & Co [1983] 1 All ER 583](https://www.lawteacher.net/cases/jeb-fasteners-v-marks-bloom.php). Disclaimers addressed to third parties are not automatically effective, as the High Court confirmed in Amathus Drinks Plc v EAGK LLP [2023] EWHC 2312 (Ch), where a buyer's negligence claim against a due diligence accountant was allowed to proceed to trial despite a Bannerman-style disclaimer, because of the continuing and direct relationship between the buyer and the adviser. Breach is established through independent expert evidence, reconstructing what a reasonably competent adviser in the relevant discipline would have done with the same information and identifying precisely where the defendant fell short. A claimant must then show what would have happened on competent advice: that the price would have been renegotiated, that protective warranties would have been sought, or that the transaction would not have proceeded at all. This is often where claims succeed or fail. Finally, recoverable loss must fall within the [scope of the adviser's duty](https://professionalnegligenceclaimsolicitors.co.uk/scope-of-duty-in-professional-negligence-cases/). The governing principle, established in South Australia Asset Management Corp v York Montague Ltd [1997] AC 191 and refined by the Supreme Court in [Manchester Building Society v Grant Thornton UKI LLP [2021] UKSC 20](https://professionalnegligenceclaimsolicitors.co.uk/the-impact-of-manchester-building-society-v-grant-thornton-on-the-law-of-professional-negligence/) and BPE Solicitors v Hughes-Holland [2017] UKSC 21, distinguishes an adviser who supplied a discrete piece of information for the client to weigh in its own decision from one who advised on the transaction as a whole. Identifying which category applies is often decisive in valuing a claim. ## What Compensation Can Be Recovered? Depending on the scope of duty found to apply, recoverable losses in a negligent due diligence claim can include the overpayment on acquisition, being the difference between the price paid and the target's true value at completion, wasted professional fees and transaction costs, the cost of remedying liabilities the diligence exercise should have flagged, and financing costs incurred on borrowing raised to fund the purchase. Where the target's true financial position only emerges once trading has begun and the business cannot be rescued, the buyer may face insolvency proceedings against the acquired company itself, a scenario in which specialist advice, such as that provided by [windinguppetitionsolicitors.co.uk](https://windinguppetitionsolicitors.co.uk/), becomes urgently necessary alongside the negligence claim. ## Time Limits for Bringing a Claim Claims of this kind are subject to the standard [limitation period in professional negligence](https://professionalnegligenceclaimsolicitors.co.uk/what-is-the-limitation-period-for-a-professional-negligence-claim/) actions: six years from the breach in contract, or six years from the date damage was suffered in tort, ordinarily completion. Where the defect in the due diligence only came to light later, [section 14A](https://professionalnegligenceclaimsolicitors.co.uk/limitation-periods-in-professional-negligence-section-14a-and-recent-developments-in-the-uk/) of the Limitation Act 1980 may extend time to three years from the date of knowledge, subject to an absolute fifteen-year longstop. Because losses on a business acquisition can take time to crystallise, obtaining specialist advice on limitation early is essential. ## Why Instruct LEXLAW Negligent due diligence claims sit at the intersection of company law, accountancy practice, and complex causation arguments, and they are almost always defended robustly by professional indemnity insurers. At [LEXLAW](https://lexlaw.co.uk/), our solicitors and barristers work together from a single set of chambers in Middle Temple, assessing the merits of a claim with the rigour of trial counsel from the first conference. Our experience spans [financial negligence claims](https://professionalnegligenceclaimsolicitors.co.uk/financial-negligence-claim-solicitor/) against accountants, solicitors, and corporate finance advisers, alongside related expertise in [HMRC and tax disputes](https://taxdisputes.co.uk/) and, where an acquisition has left a company facing insolvency, [winding-up petitions](https://windinguppetitionsolicitors.co.uk/) and creditor pressure. That combination allows us to identify every viable defendant and every recoverable head of loss, rather than treating your matter as a single, isolated dispute ### Want legal advice on the merits of your case? Your legal enquiry goes immediately to our PN litigation team in Middle Temple, London. We can't take on low value cases or give free legal advice - our minimum fee is £1750 +VAT for a conference with a solicitor and barrister. Call us on +442071830529. [Check My Case Now ✔](https://professionalnegligenceclaimsolicitors.co.uk/litigation-case-assessment-form/) ### Frequently Asked Questions (FAQ's) Can I claim if the business I bought simply turned out to be a bad investment? Not on its own. The courts distinguish between ordinary commercial risk and genuine professional failure. You need to show the adviser's due diligence fell below the standard of a reasonably competent practitioner, not just that the business underperformed with hindsight Who can I bring a claim against? Whoever was negligent in the workstream that failed, most commonly the accountants who reviewed the financials, the solicitors who handled legal due diligence, or the tax adviser who missed a liability. If several advisers were involved, more than one may share responsibility What if the due diligence report was prepared for the seller, not for me? You may still have a claim. Where the adviser knew a specific buyer would rely on the report for a specific transaction, a duty of care can arise even without a direct retainer, and disclaimers are not always effective at excluding it. How do I prove the negligence actually caused my loss? You need to show what you would have done with competent advice, renegotiated the price, insisted on different warranties, or walked away entirely. This causation element is often where claims are won or lost, so early expert input matters. How long do I have to bring a claim? Generally six years from completion. If the negligence only came to light later, you may have three years from the date you discovered it, subject to an absolute fifteen-year cut-off. Because losses on a business purchase can take time to surface, it's worth getting advice on limitation as soon as concerns arise.