The 8-Week Time Bar for NEC Compensation Events

The 8-week time bar costs subcontractors more money than any other procedural rule in NEC contracting. Not because it is obscure — it appears in plain sight in clause 61.3 — but because it is easy to miss in the pressure of running a live contract. Events accumulate, programmes slip, information arrives late, and by the time you sit down to assess your compensation event entitlement, the deadline has passed. The underlying claim is legitimate. The loss is real. The time bar means none of it matters.

This guide explains how clause 61.3 works, when the clock starts running, where subcontractors get caught, and what a disciplined notification process looks like. Read this alongside the compensation event notification guide and the quotation response guide for a full picture of the CE procedure.

What the Contract Actually Says

NEC4 clause 61.3 imposes an obligation on the Contractor to notify the Project Manager of a compensation event if the PM has not already done so. The notification must be made within eight weeks of the Contractor becoming aware of the event.

The consequence of late notification is stark. If the Contractor notifies after the eight-week period, the PM is entitled to decide that the Prices, the Completion Date, and the Key Dates are not to be changed. This is not a discretionary reduction — the PM does not weigh up how late the notification was, how genuine the event is, or how significant the impact might be. The contractual effect is a complete bar on the claim. A meritorious compensation event with a six-figure impact can be extinguished by a missed notification deadline.

This is fundamentally different from JCT forms. Under JCT, lateness in giving notice may affect entitlement, but it rarely bars a claim entirely. Under NEC, the time bar is binary: notify in time, or lose the right to claim.

The wording matters. A mention in a site meeting, a verbal query to the PM, or a reference in a progress report does not satisfy clause 61.3. The notification must be a formal, written communication that identifies the event as a compensation event under the contract.

When Does "Awareness" Start?

The eight weeks runs from when the Contractor "becomes aware" of the event. This is the most frequently litigated aspect of the time bar, and the courts and adjudicators have been consistent: awareness is an objective test.

It does not matter when you subjectively realised you had a claim. The question is when a reasonable contractor in your position would first have had knowledge of the event. You cannot argue that the clock did not start because your commercial team had not yet turned their attention to the issue, or because the full impact had not yet crystallised.

Four things that do NOT start the clock deserve attention. The date the event occurred is not necessarily the awareness date — if information arrives progressively, awareness may follow. The date you quantified the impact is irrelevant: notification and quotation are separate steps, and you do not need to know the financial effect before notifying. The date the event concluded cannot defer notification for ongoing events — awareness arises when you first identify the event, not when it finishes. The date you first raised the matter informally — in conversations, emails, or progress reports — does not satisfy clause 61.3 and does not pause the time bar.

For slow-onset events, pinpointing the awareness date is genuinely difficult. Unforeseen ground conditions under clause 60.1(12) may emerge gradually as excavation proceeds. Adverse weather events under clause 60.1(13) require comparison between experienced conditions and historical ten-year data — analysis that cannot always be completed contemporaneously. Cumulative scope changes, where individually minor instructions combine to create a significant overrun, may not clearly crystallise until the project is well advanced. In each case, the awareness date is contestable, but the burden of arguing a later date falls on you. Notify early.

Common Scenarios Where Subcontractors Get Caught

Access delays are among the most frequently missed time bars. A restriction begins modestly — a gate that opens late, a sequencing issue that costs half a day. The subcontractor tolerates it, assumes it will resolve, and does not notify. Six weeks later, it has compounded into a significant programme impact. An adjudicator will ask when a reasonable contractor would have become aware that the restriction had the potential to affect Prices or the Completion Date. The answer is usually far earlier than the date on the notification.

Late information is a similar trap. Under clause 60.1(1), late or changed PM instructions are compensation events. When a subcontractor receives late design information and works around it — re-sequencing, using provisional solutions, absorbing cost as part of normal operations — the notification clock is still running. Managing the situation does not mean you were not aware of a compensation event.

Ground conditions that worsen progressively create particular difficulty. You encounter material harder than expected. Initial investigation suggests the problem is localised. Your crew adapts. Four weeks later, it has expanded significantly. When were you aware of a clause 60.1(12) event? The honest answer is often that awareness started when the first material was encountered — even if the full extent was not yet clear. Waiting for a complete picture is the wrong approach.

Verbal PM instructions are a persistent problem. The PM gives an instruction on site. Work proceeds accordingly. No written confirmation follows. Several weeks later, a dispute arises over whether the instruction was given, and the time bar has expired. Under NEC, instructions should be in writing. If they are not, clause 13.6 provides a mechanism to confirm verbal instructions — but the obligation to use it rests with you.

Can the Time Bar Be Modified?

The eight-week period is the NEC4 default. It can be changed in Contract Data Part 1, and this happens more frequently than many subcontractors appreciate. Some contracts reduce the period to four weeks. Some reduce it further for specific categories of event. Others extend it, or remove the time bar for certain defined events.

A four-week period is serious. On an active project with concurrent programmes and a busy delivery team, four weeks passes quickly. Bespoke Z clauses — additional conditions that take precedence over standard NEC terms — can also impose additional requirements before a notification is valid: a prescribed form, a specific portal, or countersignature by a commercial manager. Each adds procedural complexity that can inadvertently delay your notification. Whatever period applies, it runs from day one. There is no grace period for settling in.

What Happens If You Miss the Deadline

If you notify late, the PM is entitled to decide that the Prices, Completion Date, and Key Dates are not affected. In practice, the PM issues a notification under clause 61.4 stating that the contractor notified too late. The claim is closed.

Your options at that point are limited. Accept the loss, or refer the matter to adjudication arguing that you were not in fact aware of the event before the date you claim. An adjudicator can revisit the PM's decision and reach a different conclusion on the awareness date.

The difficulty is that the burden of proof lies with you. You must demonstrate that a reasonable contractor in your position could not yet have been aware of the event at the date you claim awareness began. Contemporaneous records — site diaries, correspondence logs, records of what information was available on which date — are the only material that can support this argument. Without them, an adjudicator has little to work with other than the dates of the events themselves, and those dates rarely support a late awareness claim.

How to Protect Yourself

Maintain a compensation event register from mobilisation. Every potential CE — whether or not you are certain it qualifies — should be logged with the date first identified, the notification deadline, and the date notification was submitted. This is the primary defence against the time bar.

Set rolling reminders at six weeks from the date you first identify each potential CE. This gives you two weeks to prepare and submit the notification before the deadline, with some margin for unexpected pressure on the programme.

Notify early, price later. Clause 61.3 requires you to notify the event. Clause 62 deals with quotations. A notification that identifies the event and the clause it arises under is sufficient — even without a quantified cost or programme impact. Follow the compensation event notification process to make sure your notification is complete. When you submit a quotation, follow the CE quotation response guidance to ensure compliance.

If in doubt, notify. The cost of notifying an event that does not qualify is negligible. The cost of missing a genuine CE is total loss of entitlement. When there is any realistic prospect that an event qualifies, notify it.

Keep contemporaneous records that establish when you first became aware of each issue. A site diary entry recording "encountered unexpectedly hard material in Zone 3 — samples taken for analysis" is worth more than a retrospective statement when an awareness date is disputed six months later.

The Subcontractor Position

Everything above applies in NEC subcontracts as it does in main contracts. The Contractor under the main contract takes the PM role in the subcontract. The same clause 61.3 obligation, the same notification period, the same complete bar on late claims.

Subcontractors face an additional layer of risk. If a compensation event in your subcontract originates from an event at main contract level, the main contractor must pass that CE up to the PM at the same time as they administer it downwards to you. In practice, they often do not. This creates a double time bar risk: if the main contractor misses their window, they have a strong incentive to argue you were aware earlier than you claim — because they have already lost the ability to pass the cost upwards.

When you identify a CE that may have a main contract dimension, put the main contractor on notice in writing immediately. If they fail to act on it, that failure is their problem — but only if you have a written record of when you raised the issue. For a broader view of NEC subcontract terms worth checking before signing, the subcontractor contract review checklist covers the key payment and risk clauses alongside notification requirements.

The 8-week time bar will not stop catching subcontractors out. A CE register, early notification habits, and a clear understanding of when the clock starts running will protect entitlement that would otherwise be lost entirely.