The fresh report of Coventry & Warwickshire Development Partnership LLP v Avison Young (UK) Ltd [2026] EWHC 2319 (TCC) should make every project manager, quantity surveyor and contractor involved in major works stop and review how payment certifications are handled.
The Technology and Construction Court enforced an adjudicator’s award of £8,729,179.33 plus interest against Avison Young after finding that the project manager had negligently over-certified payments due to Buckingham Group Contracting Ltd. Avison Young challenged the award on jurisdiction, inadequate reasons and fair-process grounds, but the Court rejected each argument.
This is not a finding that every payment certificate creates a multi-million-pound liability. It is, however, a clear warning that certification is not an administrative formality. When a contractor becomes insolvent and an employer cannot recover overpayments, attention can quickly turn to the professional who approved the figures.
The case is particularly relevant to businesses arranging General Contractor Liability Insurance, Construction Contractor Insurance and Professional Indemnity cover across Essex, Kent and London.
The Gateway South dispute in brief
Gateway South was a 215-acre industrial and logistics park in Coventry, built on the site of a former sewage treatment plant. The earthworks were substantial, involving roughly five million cubic metres of material to create an environmental bund.
Buckingham Group was the contractor. Avison Young acted as project manager and supervisor, with responsibility for assessing and certifying Buckingham’s monthly payment applications.
The employer alleged that Avison Young had accepted reduced baseline volumes without proper investigation, taken Buckingham’s progress claims largely at face value despite conflicting information in its own records, and failed to identify defects and non-compliant work before certifying payments.
Buckingham went into administration in 2023. The employer claimed it had been left with a £25.4m overpayment and no realistic prospect of recovering that money from the insolvent contractor. It therefore pursued Avison Young.
An adjudicator found that Avison Young had failed to exercise the required reasonable skill and care. The award was £8,729,179.33 plus interest. When Avison Young refused to pay, the employer sought enforcement in the TCC.
The Court’s decision was concerned with enforcing the adjudicator’s award. Adjudication is not a final determination, so the underlying decision can still be challenged in later proceedings. Even so, the practical message is hard to miss: the “pay now, argue later” nature of adjudication can create immediate financial pressure.
1. Certification is a professional responsibility, not a paperwork exercise
The first lesson is for project managers, contract administrators and quantity surveyors. A payment certificate is not simply a record of what the contractor says it has done.
A professional certifier is expected to apply independent judgment. That does not mean measuring every cubic metre personally on every occasion, but it does mean asking whether the information provided is consistent with site observations, drawings, programmes, surveys, previous certificates and known defects.
In the Avison Young case, the employer’s complaint was not simply that the final valuation was wrong. It was that the project manager had accepted a changing baseline and progress data without properly reconciling the information available.
That distinction matters. A mistake can happen despite a reasonable process. A claim becomes much more difficult to defend where there is little evidence of a process at all.
Project managers and QSs should keep clear notes explaining what information was reviewed, which figures were challenged, what assumptions were made and why a certificate was approved. The records should show professional judgment rather than a rubber stamp.
2. Keep your own measurement records
The second lesson is straightforward: do not rely solely on the contractor’s numbers.
Contractors and subcontractors need accurate records because their payment applications, variations and progress claims may later become central evidence in a dispute. Employers and certifiers need their own records so they can test those claims rather than simply reproduce them.
This is especially important on earthworks, remediation, demolition and other projects where the measurement is difficult to verify after the work has been covered, moved or altered. Photographs, surveys, daily records, marked-up drawings, delivery tickets and site instructions can all help establish what was actually completed.
Where a baseline volume changes, the reason should be documented and approved through the correct contractual process. A lower baseline can make the percentage of work completed appear higher, which may affect every later payment certificate.
The same principle applies to defects. If work is incomplete or defective, that fact should be recorded before sign-off. It may be necessary to obtain technical advice, issue notices, retain sums or adjust the valuation, depending on the contract.
3. Insolvency changes who carries the practical risk
The third lesson concerns contractor insolvency.
An employer may have contractual rights to recover an overpayment from a contractor, but those rights can be of limited practical value once the contractor enters administration or liquidation. The employer may then look for another party whose actions allegedly caused the loss.
That does not mean project managers automatically become responsible for a contractor’s insolvency. The adjudicator in this case was not treating Avison Young as an insurer of Buckingham Group’s financial health. The issue was the alleged loss caused by negligent over-certification, with the contractor’s insolvency making recovery from the original recipient unrealistic.
This distinction is important for all parties. A general contractor, subcontractor or project manager should understand where responsibility sits under the contract, who has authority to certify payment, and what happens if one party becomes insolvent.
Contract terms should be reviewed before the project begins, not after the first payment dispute. Pay particular attention to liability caps, professional duty wording, reliance on third-party information, payment certification responsibilities, adjudication provisions, collateral warranties and any obligation to maintain insurance.
For contractors and subcontractors, good records also protect against allegations that claims were knowingly exaggerated or inadequately supported. For project managers and QSs, the same records may be essential to defending a professional negligence claim.
4. General Contractor Liability Insurance is only one part of the protection
The fourth lesson is about the difference between insurance covers.
General Contractor Liability Insurance, often arranged as part of wider Construction Contractor Insurance, is primarily designed to respond to third-party injury or property damage arising from the contractor’s work. It may also address certain legal costs and related liabilities, depending on the policy wording.
It is not normally a substitute for Professional Indemnity insurance. A payment certification error, negligent measurement, design mistake or failure to provide professional advice may result in a pure financial loss, without any physical injury or property damage. That is the type of exposure that may need PI cover.
Employers’ liability is a separate legal requirement for most businesses with employees. Contract works insurance protects the physical works, materials and sometimes temporary structures against insured damage. Business interruption may help with lost income after an insured event.
These covers work together, but they do not all respond to the same claim. A project manager who has General Contractor Liability Insurance but no suitable PI policy could still face a serious gap if the allegation is negligent certification.
The same applies to contractors offering design-and-build services, technical advice or project management. The more professional judgment the business provides, the more important it is to review PI requirements alongside public liability and contract works.
5. Check PI exclusions before a dispute starts
The fifth lesson is to read the policy before a problem arises.
Professional Indemnity policies are commonly written on a claims-made basis. This means the timing of notification, the policy in force when a claim or circumstance is first known, and the retroactive date can all be important.
A business should understand how its policy treats insolvency of another party, contractual liabilities assumed under an agreement, defects, rectification costs, adjudication awards and claims arising from guarantees or warranties. Some liabilities may be excluded, restricted or subject to specific extensions. Cover for adjudication-related costs or awards is not automatic and must be considered in the context of the actual wording.
If a project manager or QS becomes aware of a complaint, request for information, threatened adjudication or possible over-certification, the insurer and broker should be notified promptly. Waiting until formal proceedings begin can create avoidable arguments about late notification or a known circumstance.
Contractors should also notify their insurers early if a client alleges overpayment, misrepresentation of progress, defective work or breach of contract. Even where the initial complaint appears manageable, it may develop into a substantial claim once insolvency or recovery problems enter the picture.
Cover should be arranged and reviewed before the dispute, not after it. Once a business knows about a potential claim, it may be too late to purchase a policy that responds to that particular circumstance.
What businesses in Essex, Kent and London should do now
For project managers and QSs, the immediate priority should be a review of certification procedures. Ask whether the business has independent measurement records, documented checks against contractor data, a clear escalation process for changing baselines and a consistent method for recording defects.
For contractors and subcontractors, review payment applications, variation records and evidence supporting progress claims. Make sure the policy reflects the actual work being carried out, including any design, supervision, hot works, excavation, height or depth exposures.
For all construction businesses, review the relationship between General Contractor Liability Insurance, Professional Indemnity, employers’ liability and contract works insurance. Check the limits, excesses, territorial scope, contractual liability provisions and notification requirements.
At Moyak Insurance Services, we take an individual approach because no two construction businesses carry exactly the same risk. A growing contractor in Essex, a specialist subcontractor in Kent and a project management consultancy in London may all need very different combinations of cover.
The Construction Contractor Insurance guidance on our website explains why a standard policy is not always enough. We can also review General Contractor Liability Insurance and wider commercial combined business insurance with the realities of your contracts and projects in mind.
The Avison Young ruling is a reminder that insurance cannot repair poor records or replace sound contract administration. But the right cover, arranged early and understood properly, can make the difference between managing a serious allegation and facing an uninsured financial loss.
Sources and further reading
Brodies case note on professional negligence, over-certification and adjudication enforcement
Insurance Business UK report, 30 September 2026
The ruling was also reported by Estates Gazette on 29 September 2026 and Devon Shires on 23 September 2026.