Construction Act
The certificate is for less than I applied for. What about the difference?
You applied for forty, the certificate says thirty-two. The eight thousand did not vanish, but it did just change status, and what you do in the next fortnight decides whether it comes back next month or gets argued about at the final account.
QScope Team·27 May 2026·5 min read
First, the uncomfortable mechanics. On most jobs the certificate is the payment notice under section 110A: a statement of the sum the payer considers due and the basis for it. Served on time, it usually sets the notified sum, which means the client who pays the certified thirty-two in full has complied with section 111, even though you applied for forty. Being certified down is not, by itself, anyone breaking the payment rules.
Why the difference is deferred, not lost
Interim valuations are cumulative: each one values the whole of the work done to date, and the certificate pays the movement since last time. Work genuinely done but certified low this month is still there to be valued next month, on top of whatever you build in between. The system is self-correcting, provided somebody keeps applying for the full figure with better evidence each time. The money that actually gets lost is the difference nobody re-applies for, which quietly falls out of the account.
What to do, in order
1. Read the basis before you argue. The notice must state how the figure was reached. Find the lines that moved: measure, quality, a deduction. Each has a different answer, and a deduction against the sum has its own rules, see paying less.
2. Answer the reason, not the number. If they cut the steel because there is no delivery record, the reply is the delivery record, not a protest. Re-apply next cycle with the evidence attached. This is where most differences quietly come back.
3. Escalate when the same difference survives two cycles with evidence. On jobs the Construction Act covers, adjudication under section 108 exists precisely for the true value of an interim: about a month to a decision. Weigh it against the sum, because both sides carry their own costs in practice.
4. Do not stop work on the strength of being certified down. If the certified sum is being paid on time, the statutory ground to suspend is not there. The remedy is valuation, not walking.
On a job for someone living in the house
The Act, its notified sum and its adjudication do not apply to a contract with a residential occupier (section 106). Where a domestic contract runs certificates through an architect, the certificate binds the way the contract says it does, and a persistent shortfall is a contract argument headed for a letter before action and, if it must, the county court. The discipline of applying with evidence, cumulatively, is identical; only the escalation route differs.
Where the information stops
Whether to adjudicate, and on what question, is a judgement about tactics as much as entitlement, and a badly framed reference wastes the fee. When the standing difference is serious money, spend an hour with a construction solicitor or an experienced adjudication practitioner before you refer, not after.