The NEC Key Date definition joins two things: a date, and a Condition that the work has to meet by that date. Both are stated in the Contract Data and either can later change under the contract. A Key Date doesn't mean a part of the works is finished. It means a specific state of affairs has been reached by a specific day.
The definition is in clause 11.2 (item 9 in NEC3 ECC), with the duty to meet each Condition at 30.3. You'll use it most where someone else depends on the Contractor's progress. There's more on managing them in the Key Dates guide. This page is part of the NEC definitions glossary.
How it compares with other dates
| Key Date | Sectional Completion (Option X5) | |
|---|---|---|
| Measures | A stated Condition | Completion of a section of the works |
| Does the Client take over? | Not as a result of it | Yes, generally following Completion of the section |
| If missed | Contractor pays the Client's extra cost, as assessed (25.3) | Delay damages if Option X7 applies |
| Starts any Defects clock? | No | Correction periods can follow Completion |
Writing a good Condition
Most Key Date disputes come down to a Condition nobody can test. Compare these examples:
| Weak Condition | Better Condition |
|---|---|
| "Roof finished" | "Roof weathertight to grid lines A to F, so that the fit-out contractor can start work in the rooms below" |
| "Enabling works complete" | "Diverted gas main live and old main capped, with the gas company's confirmation issued to the Project Manager" |
| "Ready for signalling" | "Cable route between chainages 100 and 450 clear, with trays installed and inspected" |
A good Condition says who needs it, what they need, and how you'd prove it. If you have to ask the Contractor whether it's been met, it's too vague.
A worked example
A fictional hospital wing, with illustrative figures. Key Date 1 is 14 March, and the Condition is that plant room access is clear and level for the Client's separate equipment installer. The Contractor reaches the Condition on 28 March.
- The installer can't start, and charges the Client £9,000 for two weeks of standing time and a further visit.
- The Project Manager assesses that the Contractor's failure caused the extra cost, and the Contractor pays it under 25.3.
- Nothing changes for the Completion Date, as it's a separate test.
- If the late date was itself due to the Project Manager giving an instruction, that's a different matter. A compensation event may move the Key Date first, so that the Condition wasn't met late at all.
Note the shape of the remedy. There's no pre-set rate as with delay damages, so it depends on real, provable extra cost to the Client. That makes clear records important for both sides.
Changing a Key Date
- The Project Manager can change a Key Date by instruction (14.3). That's a compensation event under 60.1(4).
- Other compensation events may also delay a Key Date. The assessment then measures how much later the planned date for meeting the Condition becomes compared with the Accepted Programme (63.5, or 63.3 in NEC3).
- If a Scope change makes the Condition's wording wrong, the Project Manager corrects it, which is taken into account in the event's assessment (63.11 in the NEC4 subcontract text).
What people get wrong
- Using a Key Date as a milestone for payment. It doesn't produce a payment. If you want payment tied to progress, use the Activity Schedule or another route.
- Listing too many. Every Key Date means a Condition to police. Keep them to the real interfaces.
- Leaving them off the programme. Clause 31.2 requires the programme to show them, and when each Condition is planned to be met. That planned date is what later assessments rely on.
- Thinking only the Contractor's progress counts. Early warnings also cover delay to meeting a Key Date, so raise one as soon as you see a problem. See what should be an early warning.
Related guides
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