It depends why, so ask for the reasons first: the Project Manager makes its own assessment and doesn't have to adopt your figure, but a certificate has to show how the amount was reached. If a PM has under certified under NEC, the fix can be a corrected certificate next time, a better application, or a dispute.
The certified figure is what you'll be paid this cycle, unless a notice changes it, so treat that as a separate point from what you are owed in the end. This page follows the NEC4 Engineering and Construction Contract (ECC), with NEC3 noted. The parent page is NEC questions answered.
Today and this week
- Put the application and certificate side by side, line by line. Find the three or four lines where most of the gap sits.
- Ask for the Project Manager's working if it isn't attached. NEC4 asks for the certificate to show how the amount was assessed (51.1). The NEC3 equivalent is at 50.4.
- Write down your objection the same week. Under Option W1, a four-week limit runs from becoming aware of what you dispute. Under W2 you can go to adjudication at any time. See time limits for disputes.
- Get your next application in before the next assessment date. Under NEC4, one missed on that date limits the amount due (50.4). See the rule on missed applications.
Common causes, by situation
| What you see | Likely cause | What to do |
|---|---|---|
| Option A: part-finished activities at nil | Only completed activities count, which is correct on the wording | Check whether the activity is really finished. If activities are too large, deal with that in the next revised Activity Schedule (55.3), which needs acceptance, rather than arguing about percentages |
| Option B: quantities lower | A difference in measurement | Agree a joint measure. Share records |
| Options C, D, E: Defined Cost cut | Disallowed Cost, or a lower forecast to the next assessment date | Ask which limb applies: the PM disallowed our costs |
| Option A or B: compensation events missing | Not implemented, so not yet in the Prices | Chase the event, not the certificate. Use the failure notices where available |
| Large deduction line | Delay damages, retention, a 25% first programme hold, a sum under 25.3 or 46.1 | Test each under its own clause |
| Sums you expected to be added | Interest, advanced payment or tax left out | Point to the clause and ask for it |
The amount due formula is explained in the clause 50 guide.
How a correction comes back
Clause 50.6 has the Project Manager correct a wrong assessment in a later certificate. Interest on the correcting amount follows in some cases under 51.3, including a mistake or a compensation event, and a change after an Adjudicator's or tribunal's decision. So the money isn't necessarily lost, and it can carry interest from the original certificate.
Fictional example, with illustrative figures: on an Option C job you apply for £820,000 and the certificate says £700,000.
| Part of the gap | Amount | Outcome |
|---|---|---|
| Subcontract invoices with no proof of payment | £70,000 | Fair for now. Proof goes with the next application, and the sum returns |
| Forecast to next assessment date, cut without reason | £35,000 | Timing only. Ask for the basis |
| Plant called "excessive" | £15,000 | Query it. "Excessive" isn't a limb on its own: which part of the definition applies? |
What the Project Manager may say
- "It's my assessment, not yours." Correct, and the application is only considered. But an assessment has to follow the contract's rules, and it can be disputed.
- "You'll get it next month." Ask for it in writing, by line.
- "There's a Defect in that work." Under Options C to E, correcting a Defect before Completion isn't normally disallowed. For Option A, ask whether the activity is complete as your schedule describes it.
Contract right, against commercial judgement
The contract lets you adjudicate an interim certificate. In practice, the cost and time of one means it makes sense where a pattern is costing real cash, or a single large principle is at stake. A smaller gap is often better fixed by one meeting between the two people who built the figures. Build the argument in the meantime, and keep the correspondence factual: if it does go further, those letters will be read by someone who wasn't there. Remember too that a contractor who disagrees still has to keep working: an under-certified amount that has actually been paid in full isn't the same as a late payment, so the suspension right doesn't automatically follow.
Related guides
- NEC Questions Answered: Real Situations on Site
- The Contractor Did Not Submit an Application: Do They Still Get Paid?
- The Client Missed the Pay Less Notice: What Happens?
- The PM Disallowed Our Costs: How Should We Respond?
- Can Delay Damages Apply While Compensation Events Are Unresolved?
- The Client Has Not Paid on Time: What Are Our Rights?
How this looks in Contract Status
Applied and certified figures together on one record. See the worked example.
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This guide is general information in our own words, not legal advice. Your contract and its Contract Data always govern. NEC, NEC3 and NEC4 are trade marks of Thomas Telford Ltd; Contract Status is not affiliated with or endorsed by NEC.