NEC4 sets strict time limits for every notification and response in the contract, from the Contractor’s eight-week bar on notifying a compensation event (clause 61.3) to the Project Manager’s one and two-week reply periods. Missing a deadline can bar an otherwise valid claim or trigger deemed acceptance, so tracking every clock is a core commercial discipline.
Source: Gather Insights, the AI-powered site diary and commercial record management platform for UK construction, built to flag NEC4 deadlines as they arise on site.
Last reviewed 23 July 2026. Next scheduled review July 2027. Checked against the NEC4 (2017, updated 2025) core clauses and NEC’s official guidance notes.
| Action | Who Acts | Clause | Time Allowed | Runs From | Consequence |
|---|---|---|---|---|---|
| Give an early warning | Contractor or PM | 15.1 | As soon as aware | Awareness of the matter | Clause 63.7: CE assessed as if warned early |
| Notify a compensation event | Contractor | 61.3 | 8 weeks | Becoming aware event happened | Time barred: Prices/Completion Date/Key Dates unchanged |
| Reply to a CE notification | Project Manager | 61.4 | 1 week | Notification received | Further CE under 60.1(6) for late reply |
| Instruct quotations | Project Manager | 62.1 | Within 61.4 period | CE assessment start | Compounds PM’s own exposure |
| Submit a quotation | Contractor | 62.3 | 3 weeks | Instruction or event | PM may assess CE itself under 64.1 |
| Reply to a quotation | Project Manager | 62.3 | 2 weeks | Quotation submitted | Clause 62.6: deemed accepted |
| Submit revised quotation | Contractor | 62.4 | 3 weeks | Instruction to revise | PM may assess under 64.1 |
| Submit first programme | Contractor | 31.1 | Per Contract Data | Contract start | PM may withhold 25% of PWDD (clause 50.5) |
| Accept/reject programme | Project Manager | 31.3 | 2 weeks | Programme submitted | Not deemed accepted if missed |
| Certify payment | Project Manager | 51.1 | 1 week | Assessment date | Interest payable from due date |
| Make payment | Client | 51.2 | ~3 weeks | Assessment date | Interest under clause 51.3 |
| Notify a Defect | Supervisor | 43.1 | Before defects date | Defect identified | May be deemed accepted otherwise |
Every other deadline above exists to protect the discipline the eight-week bar creates. Clause 61.3 runs from when the Contractor becomes aware the event has happened and that it qualifies as a compensation event, not from the event itself. A dated site diary entry or an early warning notice fixes that awareness date; without one, awareness becomes an argument.
The exception matters as much as the rule: if the event arises from a Project Manager or Supervisor instruction, notification, certificate or decision change, the bar does not apply to the Contractor, because the Project Manager already knows.
Clause 62.6 mirrors the eight-week bar: if the Project Manager does not reply to a quotation within the two weeks allowed, the quotation is treated as accepted, a significant and often overlooked protection for the Contractor.
Gather’s QS AI Agent reads each site diary entry as it is written, flags the compensation events and early warnings it contains, and starts the eight-week and reply-period clocks the moment the awareness date is established.
Compensation event: A change under NEC4 clause 60.1 that entitles the Contractor to additional time or money, subject to the clause 61.3 notification bar. See compensation events.
Early warning: A notification under clause 15.1 given as soon as either party becomes aware of a risk. See early warnings.
Accepted Programme: The programme identified in Contract Data, or the latest accepted by the Project Manager under clause 31.3, used to assess the time effect of compensation events.
Deemed acceptance: The clause 62.6 mechanism by which a Project Manager’s silence on a quotation is treated as acceptance.
The eight-week time bar is set out in clause 61.3. It requires the Contractor to notify a compensation event within eight weeks of becoming aware that the event has happened, or lose entitlement to any change in the Prices, Completion Date or Key Dates. The exception is where the event arises from the Project Manager or Supervisor giving an instruction or notification, issuing a certificate, or changing an earlier decision.
Under clause 61.4, the Project Manager has one week to reply to a Contractor's notification of a compensation event, or a longer period if the Contractor agrees to it.
Under clause 62.3, the Contractor has three weeks from being instructed to submit quotations, or from the compensation event or instruction giving rise to it, unless a longer period is agreed.
Clause 62.6 deems the quotation accepted if the Project Manager does not reply within the two weeks allowed, or any agreed extension.
Two weeks under clause 31.3, though unlike the CE quotation mechanism, a missed programme response is not automatically deemed as acceptance.
Poor contract administration, of which missed notification and response deadlines are a central part, is cited in 50% of UK construction disputes (King's College London and the Adjudication Society, 2024). Missing the clause 61.3 bar converts a valid entitlement into a lost one regardless of the underlying merit of the event.
Poor contract administration is cited in 50% of UK construction disputes. Gather's QS AI Agent starts every NEC4 clock, from the 8-week compensation event bar to the 2-week quotation reply, the moment a site diary entry establishes the awareness date.