The final certificate, and what it closes

Interim certificates settle nothing. Everything in them can be revisited, and the final account is where that revisiting happens. The final certificate is different.

On JCT contracts, the final certificate is expressed to have conclusive effect on specified matters. That is a substantive provision with a short timetable attached, and it deserves more attention than it usually gets from either side.

What it is conclusive about

The precise wording varies by form and edition, and it should be read rather than remembered. Broadly, the final certificate is conclusive evidence that:

• Where the quality of materials or standards of workmanship were expressly stated to be for the approval of the architect or contract administrator, they are to that reasonable satisfaction
• The adjustments to the contract sum have been made in accordance with the contract, subject to accidental inclusion or exclusion of an item, or arithmetical error
• All due extensions of time have been given
• Reimbursement of loss and expense is in final settlement of all claims arising from the relevant matters

What it is not conclusive about

An important qualification, and one that is frequently overstated in both directions.

The conclusiveness on quality is limited to matters expressly reserved for the approval of the architect or contract administrator. It is not a general certificate that the building complies with the contract. Latent defects in work that was never expressly reserved for approval are not swept up by it.

The point is easy to state and easy to get wrong in practice, because the boundary depends on what the specification actually said.

The window

The conclusive effect is subject to proceedings commenced within a stated period after the final certificate is issued, commonly 28 days on JCT forms. Where adjudication, arbitration or litigation is commenced within that period, the certificate is not conclusive on the matters in dispute.

Twenty-eight days is short. On a job that has taken two years, with a final account that took four months to agree, the period in which the whole thing can still be challenged is under a month, and it starts on a date that may not be prominently communicated.

Before issuing it, client side

• Is the certificate of making good issued, and have defects been dealt with?
• Is retention fully released or accounted for?
• Has every extension of time been formally determined, not merely discussed?
• Are all loss and expense claims ascertained or formally rejected?
• Does the account reconcile: certificates issued, plus this balance, against the adjusted contract sum?
• Have any outstanding contra charges been dealt with through the contractual mechanism?

Issuing a final certificate with an unresolved item is how a contract administrator ends up in a difficult conversation with a client who assumed the point was still open.

Before the window expires, contractor side

• Does the certificate reflect what was agreed?
• Are all variations included, at the agreed values?
• Is retention accounted for in full?
• Is any element of the loss and expense claim unresolved and worth pursuing?
• If anything is wrong, is there time to commence proceedings within the window?

NEC and other forms

Do not assume this mechanism exists everywhere. NEC4 does not operate a conclusive final certificate in the JCT sense; it works through a final assessment with its own timetable and its own consequences for failing to respond.

Bespoke and amended contracts vary widely, and conclusivity provisions are a common target for amendment. Read the clause on the job in front of you rather than the clause you remember from the last one.

This is a general summary and not legal advice. Conclusive effect provisions differ between forms and editions, and the consequences of the window expiring are significant. Take advice where a challenge is contemplated.