Yes, you can challenge it, but only if you start the dispute route within four weeks of its issue; miss that and the figure stands as conclusive evidence of what is finally owed (NEC4 clause 53.3). What decides your next step is whether your contract has Option W1 or W2, and whether the assessment was issued in time.
Don't let the time go on negotiation alone. This applies to both Parties, so a Client unhappy with a Contractor's figure faces the same clock. The final assessment guide covers the clause, and this page belongs to NEC questions answered.
The clock, step by step
- Day 0: note the issue date. The PM's deadline for issuing was four weeks after the Defects Certificate, or thirteen weeks after a termination certificate (53.1). Note whether it was met.
- Within four weeks: refer it. The steps are in the table below. Book the last date now, and work to an earlier one.
- Then the Senior Representatives' stage, if you used it. Under the NEC4 subcontract text, they have up to three weeks and produce a list of issues agreed and not agreed.
- Within three weeks of that list: refer unresolved issues to the Adjudicator. The time also runs from when the list should have been produced, so a stalled meeting doesn't stop it.
- Within four weeks of the decision: refer any dissatisfaction to the tribunal, if you wish to take it further. If nobody does, the decision is folded into the assessment (53.4).
| Your contract | First referral (within four weeks) |
|---|---|
| Option W1 | To the Senior Representatives |
| Option W2 (usual where the Construction Act applies) | To the Senior Representatives or straight to the Adjudicator |
| Option W3 | Follow the steps in that Option, read together with 53.3 |
These periods are drawn from the NEC4 subcontract, which uses ECC clause numbers. Check them against your own contract, and any Z clause, before relying on them. The time limits guide has the wider picture.
What is your disagreement really about?
| The complaint | What decides it |
|---|---|
| An arithmetic or certificate error | Usually fixed by agreement. Record it in writing, as 53.4 changes the assessment for an agreement. Still protect the date |
| An open compensation event left out | Whether it was notified in time. See open events after the project ends |
| An implemented event you now think was underpriced | A hard point. An implemented assessment isn't revised (66.3) |
| Defined Cost or Disallowed Cost on Options C to E | The records. See Disallowed Cost |
| The share calculation on Options C or D | The final Prices and Price for Work Done to Date (clause 54) |
What if the PM issued late, or not at all?
The contract says if the PM misses the time allowed, the Contractor may issue its own assessment with details (53.2). The conclusive effect in 53.3 applies to an assessment issued within the stated time.
In practice, don't sit on a late assessment and assume it has no effect. Treat the four weeks as running, say in writing that the assessment was late, and take advice if the amount justifies it. If no assessment has come, issue your own, with the working behind it.
A fictional example
A fictional Option C contract, with illustrative dates. The Defects Certificate is issued on 1 May. The PM's assessment follows on 22 May, leaving out £140,000 of the Contractor's figures. The last date to refer is 19 June.
The commercial managers meet twice, and by 12 June they have agreed £60,000. The Contractor refers the remaining £80,000 on 15 June, without waiting for a third meeting. The parties record their £60,000 agreement. The dispute over the £80,000 then runs on the set timetable.
Sample wording
What the other side is likely to say
- "Let's talk first: no need for a formal step." Fine, but agree an extension only if the contract permits it, and record it. If in doubt, refer and keep talking.
- "That event was settled long ago." Have the implementation record ready.
- "You're out of time." Check the issue date, how it was served, and whether the assessment itself was on time.
On NEC3 there is no final assessment clause. Clause 53 deals with the Contractor's share, and final payment is settled through the ordinary assessment process. For practical preparation, see closing out the final account.
Related guides
- NEC Questions Answered: Real Situations on Site
- The Project Has Finished but Compensation Events Are Still Open
- Does PM Acceptance Remove Our Design Responsibility?
- Can a Main Contractor Pay Only When It Has Been Paid?
See how this works in practice
Click through Contract Status with sample contracts: raise the notice, reply to it, and watch both sides of one record.
Take the guided tour Book a demo
Use the NEC deadline calculator, use the free NEC tools or download free NEC templates.
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.