Early Warning Notices in NEC Contracts: How They Work

A groundwater issue on site, a late design change, a subcontractor flagging a supply chain delay - under an NEC contract, none of these should come as a surprise to the other party. Every NEC3 and NEC4 main option carries a mutual duty at clause 15: the Contractor and the Project Manager must warn each other the moment they become aware of anything that could raise cost, delay Completion, delay a Key Date, or make the works harder to use or maintain. That duty is the early warning notice, and it sits at the heart of how NEC contracts manage risk collaboratively rather than adversarially.

For quantity surveyors and commercial managers, understanding how an early warning notice under NEC works is not optional background reading - it is one of the mechanisms that determines whether a compensation event is assessed in full, reduced, or challenged. Get the early warning process right and risk gets managed before it becomes a claim. Get it wrong, and a Contractor can watch a legitimate compensation event entitlement shrink because the Project Manager decides an experienced contractor should have flagged the risk sooner.

This guide covers what an early warning notice actually is under clauses 15 and 16, how the Early Warning Register and early warning meetings work in practice, the crucial distinction between an early warning and a compensation event notification, and the common ways the process breaks down on live projects. We also cover the practical situations that should trigger a notice, and how QSs and PMs can run the process so it earns its keep rather than becoming another form to file.

If you are still getting to grips with how compensation events themselves work, it's worth reading our companion guide, Compensation Events in NEC Contracts: A QS Guide, alongside this one - the two clauses are designed to work together, and understanding both is essential NEC knowledge for any commercial role.

What Is an Early Warning Notice Under NEC Contracts?

The Clause 15 obligation

Clause 15.1 of the NEC4 Engineering and Construction Contract (ECC) states that the Contractor and the Project Manager give an early warning by notifying the other as soon as either becomes aware of any matter that could increase the total of the Prices, delay Completion, delay meeting a Key Date, or impair the performance of the works in use. NEC3 contains the equivalent duty, historically at clause 16. The obligation is deliberately mutual: it is not a contractor-only reporting duty, and a Project Manager who spots a risk - a late client decision, a design change, an access restriction - is just as obliged to raise it as the Contractor is.

The threshold for triggering an early warning is low by design. The matter does not need to be certain, quantified, or even the other party's fault - 'could' is enough. This is what separates an early warning from a formal claim: it is a heads-up mechanism, not an assertion of entitlement. NEC4 also widened the early warning duty in some ECC options so the Contractor must warn of matters that could increase the Contractor's total cost, not just the Prices - a subtle but important change for target-cost arrangements.

How an early warning notice should be given

An early warning notice is normally submitted through the project's Communications process - via the NEC-compliant software many contracts now specify, or a defined notice format if the contract is run on paper. It should be specific enough that the other party can act on it: what the risk is, why it matters, and, where known, what mitigation is being considered. A vague, blanket warning that 'weather may cause delay' does little to protect either party; a warning that names a specific activity, date and cause is far more useful, and far more defensible later.

The Early Warning Register and Early Warning Meetings

Every early warning raised under clause 15 is entered into the Early Warning Register, a live, contract-defined document with two required columns: a description of the risk and the action to be taken to avoid or reduce it. NEC4 renamed what NEC3 called the Risk Register and risk reduction meeting to the Early Warning Register and early warning meeting respectively - the substance is the same. Still, the naming now matches the notice that feeds it.

Clause 16.2 requires the first early warning meeting to be held within two weeks of the Contract Date under NEC4 ECC, with further meetings held as instructed by the Project Manager or Contractor, and at least as frequently as the interval stated in the Contract Data. Either party can also call the other at any time a new risk needs discussing. After each meeting, the Project Manager must revise and reissue the Early Warning Register, and NEC4 sets a one-week deadline for doing so.

The meeting itself is meant to be genuinely collaborative: attendees discuss each entry, decide what action is needed and who owns it, consider whether the risk can be shared or reduced, and remove items that have passed or been resolved. Anyone with relevant expertise can be invited - designers, subcontractors, specialists - even though only the Contractor and Project Manager carry the clause 15 duty. A register that never shrinks, or a meeting that never happens, is usually a sign the process has stalled.

How the Early Warning Process Works: Steps and Timescales

The early warning mechanism runs on a set of clear, contract-defined timescales. Missing them doesn't usually void the process outright, but it does weaken a party's position if the timing of who-knew-what-when is ever tested. The table below sets out the key steps and the NEC4 timescales that apply to each.

Note that the 8-week compensation event time bar in clause 61.3 is separate from the early warning duty, but the two interact directly, as covered below - an early warning does not extend or replace that deadline, and a Contractor cannot treat 'I gave an early warning' as a substitute for a compensation event notification when the contract requires one.

Early Warning vs Compensation Event: How They Differ and Interact

The most common confusion on NEC projects is treating the clause 15.1 early warning and the clause 61.3 compensation event notification as interchangeable. They are not. An early warning flags a risk that might happen; a compensation event notification asserts that a specific, contract-defined event has happened, or will happen, and starts the formal quotation process under clauses 61 and 62. One is prospective and informal, the other is procedural and time-barred.

Failing to give a compensation event notification within the 8-week time bar under clause 61.3 is fatal to the Contractor's entitlement to a change in the Prices, Completion Date or a Key Date, except where the Project Manager should have notified the event itself. Failing to give an early warning is not fatal in the same way - but it is not free of consequence either. Clause 61.5 allows the Project Manager to decide that an experienced contractor could and should have given an early warning that wasn't given. Where that decision is made, the compensation event is assessed as though the warning had been given on time, including whatever mitigation would then have been possible. In practice, this usually reduces the assessed Defined Cost - the Contractor still gets paid something, but less than it would have if the risk had been flagged early enough for the Project Manager to influence the outcome.

For a full walkthrough of how the compensation event process itself works - the clause 60.1 trigger list, the 8-week notification deadline, and how quotations are assessed - see our companion piece, Compensation Events in NEC Contracts: A QS Guide.

What Should Trigger an Early Warning? Practical Examples

Because the clause 15 threshold is deliberately broad, QSs and PMs are often unsure what actually warrants a notice. In practice, an early warning should be raised whenever something crosses a party's desk that could plausibly move cost, time or quality - even if it later comes to nothing.

• Ground conditions that differ from what the Site Information described, before they are confirmed as a compensation event
• A subcontractor or supplier flagging a lead-time or availability problem that could affect the programme
• A design query or missing information that is taking longer than expected to resolve
• Adverse weather forecasts that could exceed the weather data threshold in the Contract Data
• A Client decision - for example on a Key Date or an instruction - that is running later than the programme assumed
• Access, interface or third-party constraints, such as other contractors, statutory undertakers or adjacent occupiers, that could restrict the works

The test is not certainty, it's foresight. If an experienced Contractor or Project Manager, aware of the facts at the time, would reasonably have expected the matter to affect cost, time or performance, an early warning should be given - promptly, and in writing.

Common Failures: When Early Warnings Become a Box-Ticking Exercise

The single biggest failure mode is treating the early warning as paperwork rather than genuine risk management. Some project teams issue early warnings defensively - to protect a future compensation event argument - rather than to actually get the other party's help solving the problem. Others let the Early Warning Register turn into a graveyard of stale entries that nobody revisits, which defeats the purpose of the clause 16 meeting entirely.

A related failure is confusing the mechanisms: contractors sometimes assume that issuing an early warning satisfies the clause 61.3 notification duty for a compensation event, or that it 'stops the clock' on the 8-week time bar. It does neither. Equally, Project Managers sometimes ignore early warnings raised by the Contractor, treating them as the Contractor's problem to solve, when clause 15 makes early warning a two-way, collaborative obligation - and the PM's own failure to warn can matter just as much when disputes are later reviewed.

Poor record-keeping compounds both problems. If the Early Warning Register isn't kept current, isn't reissued on time, or doesn't clearly link a warning to the eventual compensation event outcome, it becomes very difficult - months or years later, in a formal claim or adjudication - to establish who knew what, and when.

Best Practice: How QSs and PMs Should Manage the EWN Process

Treat the Early Warning Register as a live commercial tool, not an administrative afterthought. Review it before every progress meeting, not just at the scheduled early warning meeting, and use it to drive decisions rather than just record them.

• Raise early warnings early and specifically - name the risk, the mechanism, the likely effect and the date it was identified
• Keep the register current: close out resolved risks, update actions, and reissue within the clause 16.4 deadline
• Use early warning meetings to genuinely problem-solve - invite the people who can actually influence the outcome, not just record-keepers
• Cross-reference every early warning against the compensation event log so the link between the two is auditable
• Train site teams to recognise trigger events on the ground, since delays in reporting up the chain often cause the biggest gaps
• Don't wait for certainty - a warning given about a risk that never materialises costs nothing; a warning withheld until it's a certainty may already be too late to help

Done well, the early warning process is one of the few genuinely collaborative mechanisms in a construction contract. It rewards the parties that communicate early and penalises, gently but measurably, those that don't.

Frequently Asked Questions

What is an early warning notice under NEC?

An early warning notice is the notification the Contractor or Project Manager gives, under clause 15.1 of the NEC4 Engineering and Construction Contract, as soon as either becomes aware of a matter that could increase cost, delay Completion or a Key Date, or impair the performance of the works. It is recorded on the Early Warning Register and discussed at early warning meetings.

Is an early warning notice the same as a compensation event notification?

No. An early warning under clause 15.1 flags a risk that might affect the project; a compensation event notification under clause 61.3 asserts that a specific, defined event has occurred and starts the formal quotation process. Giving one does not satisfy the requirement to give the other.

What happens if a contractor doesn't give an early warning?

It isn't automatically fatal to the Contractor's rights, but under clause 61.5 the Project Manager can decide that an experienced contractor should have given a warning that wasn't given. Where that decision is made, the resulting compensation event is assessed as if the warning had been given on time - typically reducing the Contractor's entitlement.

Who is responsible for giving early warnings under NEC4?

The duty is mutual. Clause 15.1 requires both the Contractor and the Project Manager to notify the other as soon as they become aware of a relevant matter - it is not a one-way reporting obligation on the Contractor alone.

How often are early warning meetings held?

NEC4 requires the first early warning meeting within two weeks of the Contract Date. Later meetings are held as instructed by the Project Manager or Contractor, and at least as often as the interval stated in the Contract Data, with either party able to call one when a new risk arises.

Does an early warning stop the compensation event time bar running?

No. The 8-week time bar for notifying a compensation event under clause 61.3 runs independently of any early warning that has been given. An early warning is not a substitute for a formal compensation event notification.

Is giving an early warning compulsory under NEC?

Yes. Clause 15.1 is an express contractual obligation, not a discretionary courtesy. Failing to give a required early warning can have real financial consequences for the Contractor even though it doesn't create the same automatic time bar as a missed compensation event notification.

Final Thoughts

The early warning notice is one of the simplest, cheapest risk management tools in the NEC suite - and one of the most under-used. It costs nothing to raise a warning that turns out to be unnecessary, but a warning withheld until a risk has become a certainty can cost a Contractor real money when a compensation event is assessed. For QSs and commercial managers, treating clause 15 as core commercial discipline - not paperwork - is essential NEC knowledge that pays for itself the first time it prevents a dispute.

Want the full picture? Want the full compensation event picture?

This early warning guide works best alongside our companion piece, Compensation Events in NEC Contracts: A QS Guide, which covers the clause 60.1 trigger list, the 8-week notification time bar and how quotations are assessed. Read both together for the complete NEC4 risk and change picture.