A Final Statement So Onerous It Was Determined Invalid

April 21, 2026

When a Final Certificate is intended to close the account, it should do exactly that, fairly, transparently and in accordance with the Contract. Yet in a recent adjudication, the Adjudicator found that an Employer’s Final Certificate under a JCT Prime Cost Building Contract 2016 was not just inaccurate, but so procedurally flawed that it was declared invalid.

What should have been a routine contractual housekeeping exercise escalated into a major adjudication, raising significant questions about the limits of professional discretion, the duty of fairness and impartiality in certification and what happens when a Final Certificate becomes a weapon rather than a record.

From routine to ruin

For more than two years, the Contractor and the project Quantity Surveyor had established a collaborative, transparent approach to monthly valuations. Each valuation was prepared, reviewed and certified on an open-book basis and reflected the evolving position of the Prime Cost and fee. However, shortly after practical completion, the QS was stood down, and a replacement QS was appointed. Within weeks, more than£1.8million was stripped out of the established final account projection.

Relying wholesale on the replacement QS’s ethically questionable ‘Recommendation for Payment’ report, the CA/Architect issued a Final Certificate stating not only that nothing was owed to the Contractor, but that the Contractor was liable to repay more than £1.1 million to the Employer.

The Adjudicator accepted the QS’s report as an “onerous” document that went far beyond what the Contract permitted.

Clause 4.22 -The Promise of Finality

Clause 4.22 of the JCT Prime Cost Building Contract requires the Final Certificate to state:

· the Prime Cost;

· the Contract Fee;

· any loss and expense due to the Contractor;

· any deductions from the Prime Cost;

· amounts previously certified as due; and

· any sums paid pursuant to Payment Notices.

In short: a clear contractual statement of account. Not a retrospective rewriting of the project’s commercial history. On behalf of the Contractor, Pyments argued that the Final Certificate was invalid because:

· It ignored two years of previously certified and agreed valuations;

· It failed to follow the Contract’s mechanisms for ascertaining Prime Costs;

· The replacement QS’s assessments reflected their personal preferences for valuation, not contractual entitlement.

The Adjudicator agreed. The Final Certificate was “wholly inconsistent with the contemporaneous valuation record”.

Key findings

Interim Valuations vs Final Revision: The Contractor demonstrated that every interim valuation had been supported by invoices, quotations and contemporaneous QS assessments. While interim valuations are not conclusive, the Adjudicator confirmed they cannot simply be discarded. He noted: “Reasonable justifications must be given to revise what had been previously certified”. The Final Certificate was therefore not a genuine finalisation, but a unilateral rewrite. That procedural failure…along with others…rendered it invalid.

Procedural Fairness in Certification: CA/Architects and QS’s must act independently, impartially and in accordance with the Contract. The Adjudicator was clear that the Employer’s late-stage attempt to re-engineer the valuation, setting parameters that were neither advised during the Works nor required by the Contract, breached that duty of fairness.

The outcome: The Adjudicator held that the Final Certificate was invalid and dismissible and determined the proper valuation under clause 4.22.2instead. The Employer was ordered to pay almost £1million within seven days. Ironically, the Employer’s attempt to recast the account not only failed but triggered the very liability it had sought to avoid. A clear reminder: changing advisors late in the day does not entitle an Employer to rewrite the past. And, as for Contractors……good contemporaneous evidence wins disputes.

A growing trend: This adjudication reflects a wider industry pattern: An increasing occurrence to issue aggressive or procedurally flawed Final Certificates in an attempt to retrospectively ‘fix’ project accounts. Pyments supports clients, contractors, sub-contractors and employers by ensuring certification and valuation processes remain credible, transparent and defensible.

Final thoughts

Ultimately, this wasn’t just a dispute about figures. It was a dispute about fairness. A Final Certificate should bring closure, not conflict. However, when certification loses its balance, the Contract, and those who understand it, will restore it.