The Eight-Week Time Bar: NEC Clause 61.3 in Practice

By Sheldon Wright MCICES. Last reviewed September 2026. Covers NEC3 and NEC4 ECC, with a note on the subcontract.

Of all the ways to lose a compensation event, this is the most complete. A contractor can be fully entitled, have perfect records and a faultless quotation, and recover nothing, because the notification went in nine weeks after the event when the contract allowed eight.

Clause 61.3 is short, and most people on NEC projects can recite the headline. Even so, I still see experienced teams, who know the rule, caught by it. They are caught by the detail: which events the bar applies to, when the eight weeks start, and what counts as a notification. This article deals with each, then with the ways registers fail in practice, and then with what a Project Manager should do with a late notification.

I paraphrase the contract throughout. Read your own clause 61.3 alongside this, and then read your Z-clauses, because this is one of the most frequently amended clauses in the form.

The one I see most often does not look like a compensation event at all.

An instruction arrives and no compensation event is notified with it. The burden of working out what it means has quietly moved to you. Most of the time that is manageable, because the change is obvious. The dangerous ones are the changes that look like housekeeping: a revised health and safety policy, a page and a half, circulated to everybody. It goes to the bottom of a long list of actions, behind the things that are visibly urgent.

Weeks later somebody reads it properly. The new policy wants a dedicated plant watcher and a fire marshal for each operation. On a programme running over several months that is tens of thousands of pounds of people who were never in the price — and the question is no longer what it costs, but whether you are still in time to say so.

Now the part worth pausing on, because it is this whole article in one example. If that policy reached you as an instruction from the Project Manager, the bar does not apply: an event arising from a Project Manager's instruction is the exception under both editions, and the clause does not punish you for their omission.

But check, because in my experience it usually was not an instruction. It came from the Client's health and safety adviser, or as an attachment to a newsletter, or as a revised standard mentioned at a progress meeting, and nobody issued it as anything. If you are a subcontractor it may have arrived as a forwarded email from the Contractor, which is not an instruction under your subcontract either.

That is the trap. The thing that felt safe because it had been "instructed" was never instructed, and the eight weeks have been running since the day you first knew about it.

What the clause does

Clause 61.3 requires the Contractor to notify the Project Manager of an event that has happened, or that the Contractor expects to happen, as a compensation event if two things are true: the Contractor believes it is a compensation event, and the Project Manager has not already notified it.

It then sets the bar. If the Contractor does not notify within eight weeks of becoming aware that the event has happened, the Prices, the Completion Date and any Key Date are not changed. The entitlement to both time and money goes.

There is one exception. The bar does not apply to events that start with a communication from the Project Manager or the Supervisor: an instruction, a notification, a certificate or a changed decision. Those are the events clause 61.1 requires the Project Manager to notify, and the contract does not penalise the Contractor for the Project Manager's omission.

NEC3 does not reach the same place, and the difference is the most important thing in this article. Under NEC3 the exception applies where the Project Manager should have notified the event and did not. Under NEC4 it applies where the event arises from the Project Manager or the Supervisor giving an instruction or a notification, issuing a certificate or changing an earlier decision. The first is a judgement about what ought to have happened. The second is a question of fact about what actually did. The next section deals with what that changes.

NEC4 also tightened the trigger: its eight weeks run from becoming aware that the event has happened, where NEC3 says becoming aware of the event.

Which events are caught

The practical split is between events that start with a communication from the Project Manager or Supervisor, and events that start somewhere else.

In the first group are an instruction changing the Scope, an instruction to stop or not start work, a changed decision, an instruction dealing with an object of value or historical interest, and similar. The Project Manager should notify these, and if they do not, the bar does not apply.

The second group contains everything else, and it is where the money tends to be:

the Client not giving access to a part of the Site by the date it should
the Client not providing something by the date shown on the Accepted Programme
the Client or Others not working within the times or conditions in the Scope
the Project Manager or Supervisor not replying to a communication within the period
a test or inspection by the Supervisor that causes unnecessary delay
unforeseen physical conditions
weather beyond the one-in-ten-year measure
a Client's liability event
prevention events.

Nobody writes to the Contractor to announce that any of these has happened. If the Contractor does not notify, nobody will, and the clock runs regardless.

Look closely at the failures to act. An instruction arrives as a document with a date on it. A failure by the Client to provide access or free-issue materials arrives as an absence, and absences are easy to live with for a few weeks while everyone works around them. By the time the workaround has clearly failed, a good part of the eight weeks has gone.

My advice to contractors is to stop sorting events into the two groups. If something has happened that you think is a compensation event, notify it, whether or not you think the Project Manager should have done so first. Arguing later that the exception applies is a poor substitute for a notification on the file.

How much of the bar is left

This gets the least attention of anything in clause 61.3, and under NEC3 it matters more than the eight weeks do.

Clause 61.1 requires the Project Manager to notify a compensation event that arises from their own action, and to instruct a quotation at the same time. NEC3's exception is tied to that duty: if the Project Manager should have notified the event and did not, a late notification does not cost the Contractor its entitlement.

Commentators on NEC3 have drawn the obvious conclusion. Most compensation events on most projects arise from something the Project Manager should have notified. If that is right, the eight-week bar bites on a much narrower set of events than its reputation suggests — the Client-side failures and the neutral events in the second group above — and for everything else the only real long-stop is clause 61.7.

NEC4 closed that gap, and this is the difference people carry across without noticing. NEC4's exception is not a test of what the Project Manager ought to have done. It asks whether the event arose from one of four things the Project Manager or the Supervisor actually did. An event that the Project Manager plainly should have notified, but which did not arise from an instruction, a notification, a certificate or a changed decision, is caught by the bar under NEC4 where it would have escaped under NEC3.

So do not run an NEC3 habit on an NEC4 job. On NEC4 the safe assumption is that the bar applies unless you can point at the communication the event arose from.

Clause 61.7 is the long-stop, and it changed too. Under NEC3 a compensation event is not notified after the defects date. Under NEC4 it is not notified by the Project Manager or the Contractor after the Defects Certificate is issued — a later date, and one that binds the Project Manager as well. Where the eight-week bar does not apply, 61.7 is what eventually ends the argument, so it is worth knowing which of the two dates governs your contract.

When the eight weeks start

The period runs from the Contractor becoming aware that the event has happened. It does not run from the event itself, from when the Contractor worked out what the event would cost, or from when the delay became critical.

Three points follow from that.

Awareness of the event, not of its consequences. The trigger is knowing the event has happened. You do not need to know the cost or the delay to notify. The notification is a short statement that an event has occurred and that you consider it a compensation event under a named clause. Quantifying it is the job of the quotation. Holding back the notification until the numbers are ready is the most common way I see the bar triggered.

There is a second cost to waiting that people do not think about. Notify late enough and, by the time anyone assesses the event, the work has been done. You will then be asked what it actually cost, rather than what you forecast it would cost, and you will be disclosing records to prove it. A forecast you control becomes an audit you do not. Even where the bar does not catch you, lateness changes what the assessment is built from.

There is a subtler version of the same problem, and it is a genuine awkwardness in the drafting rather than a trap of anyone's making. The duty to notify only arises once the Contractor believes the event is a compensation event. The clock, though, runs from awareness of the event. Those are not the same moment, and the second can be well ahead of the first: by the time belief has formed, some of the eight weeks has already gone, and on a slow-burning issue it may all have gone. The clause distinguishes between the event and the compensation event, and the eight weeks run from awareness of the event. With physical conditions, for example, the event is meeting the ground. Whether an experienced contractor would have allowed for it, which is what makes it a compensation event, may take weeks of argument to establish. The clock does not wait for that. Notify when you meet the condition, and argue about whether it qualifies afterwards.

Whose awareness? The contract does not say which individual's knowledge counts, and there is little authority on the point. The general legal position is that a company knows what its directors and managers know, and contractors have sometimes argued that they were not aware of an event until management reports showed a loss and someone identified the cause. I would not want to rely on that. For practical purposes, work on the assumption that if the site team knew, the Contractor knew. The foreman who meets an obstruction on a Tuesday has started the clock, whether or not the commercial team hears about it for a month. That makes the link between the site diary and the commercial register the most important control you have.

Events that develop over time. Some events have no clear moment: a condition that gets worse gradually, or a weather event measured over a calendar month. For weather, the natural trigger is when the month's data is available and shows the threshold was passed. For developing conditions, notify at the first point at which you could reasonably say an event has happened, and update as it develops. Early warning under clause 15 (clause 16 in NEC3) should already have been given by then, and a Contractor who warned early is in a far stronger position when the awareness date is argued.

What counts as a notification

It has to be a notification under the contract, and the contract has rules about form. Communications must be in a form that can be read, copied and recorded, and sent through the communication system named in the Scope where there is one. A notification also has to be communicated separately from other communications (clause 13.7).

That last requirement causes real damage. A paragraph in a monthly progress report, an item in meeting minutes, a line in a covering email about something else: all of these show that the Project Manager knew about the problem. None of them is reliably a notification of a compensation event. The argument that "they knew about it" is about the Project Manager's knowledge, and the clause is concerned with whether the Contractor notified.

A notification needs only a few things: a reference to clause 61.3, the event described in a sentence or two, the compensation event clause relied on, the date the event happened and the date you became aware. It takes ten minutes. It commits you to nothing on value.

One more thing, and it is the mistake I would least like to watch someone make. An early warning is not a compensation event notification. They are different communications under different clauses doing different jobs, and giving the first does not give the second. I have seen the two treated as interchangeable in an argument, and a tribunal is not obliged to untangle it for you. Say which one you are giving, on the face of the document, every time. If the same matter deserves both, send both.

How registers fail

Teams that know the rule still miss the date, and in my experience the failures are procedural.

The register starts at the notification. Most compensation event registers open a line when a notification is issued. The risk period comes before that, between awareness and notification. A register that does not record potential events, each with an awareness date and a countdown, cannot protect you.

The event lives in site records and nowhere else. The diary records standing time because of an obstruction. Nobody commercial reads the diaries that month. Some contractors now run a weekly review of site records specifically to catch events. It takes an hour, and it is the cheapest control in this article.

Notification waits for the quotation. The team intends to notify once it has a rough figure. The rough figure takes six weeks. Then someone goes on holiday.

Everyone assumes the event was instructed. The team believes the event came from a Project Manager's instruction, so the bar does not apply. On inspection, the instruction was verbal, or came from the Client's representative and not the Project Manager, or was a comment on a drawing. If the event did not arise from a communication of the kind the clause lists, the exception is not available.

The subcontract period is shorter. The NEC4 subcontract reduces the period to seven weeks so that the Contractor can pass the notification up the chain within its own eight. Bespoke subcontracts often cut it further. A subcontractor working from memory of the main form will be late.

The Z-clause moved the goalposts. Amended contracts commonly shorten the eight weeks, extend the bar to events the Project Manager should have notified, or add conditions about the content of the notification. Read clause 61.3 of your actual contract, once, at the start of the job.

If you are the Project Manager

A late notification puts an obligation on the Project Manager as well. NEC4 includes, among the tests the Project Manager applies when responding to a notification, whether the event was notified within the contract's timescales. NEC3 does not. Its clause 61.4 lists four grounds for deciding that the Prices and dates are not to change, and lateness is not among them. On a strict reading, an NEC3 Project Manager who thinks a notification is out of time still has to reply on the four grounds, and if none of them applies has to instruct a quotation, leaving the Client to rely on clause 61.3 in any dispute. In practice most NEC3 Project Managers reply that the event is time-barred and that the Prices and dates will not change. Whichever course you take, reply within the week. Silence carries its own consequences under clause 61.4 in both editions.

Two cautions from the assessor's side. First, apply the bar on evidence. You need a reasoned view on when the Contractor became aware, based on records such as diaries, early warnings and meeting minutes, because the awareness date is the point an adjudicator will test. Second, check the exception before relying on the bar. If the event arose from one of your own instructions or changed decisions and you did not notify it under clause 61.1, the bar does not help you.

A warning for Clients: the time bar and delay damages

The time bar is usually seen as a protection for the Client. There is one situation in which it may work against the Client, and legal commentators on NEC3 have raised it repeatedly.

English law has long held that an employer cannot recover liquidated damages for a period of delay that the employer itself caused, unless the contract provides a way of extending time for that delay. NEC provides one, through the compensation event. The unresolved question is what happens when the Client causes delay, the Contractor fails to notify in time, and the Completion Date therefore does not move. The Client may wish to deduct delay damages for a delay of its own making. Courts in other jurisdictions have gone both ways on comparable clauses, and I am not aware of an English decision on the NEC wording.

I am not a lawyer and I do not offer a view on the answer. The practical point is for Project Managers. Where the Client has plainly caused critical delay, staying silent and hoping the Contractor misses the eight weeks is not a safe strategy. The Project Manager has early warning duties of their own, and a Completion Date that has not moved when it should have is a weak foundation for delay damages. Take advice before deducting damages in that situation.

Where Clause 60 fits

Notification timing is one of the things Clause 60 checks when it reviews a compensation event pack. It reads the contract, including any Z-clause that amends clause 61.3, compares the event, awareness and notification dates it finds in the documents, and flags where the timing is at risk or where the pack does not contain enough to tell. Every finding is cited to its source document and labelled Fact or Inference. The review covers the cost build-up and the native Primavera P6 programme in the same pass and takes about ten minutes. It is assistive, not advisory: the judgement on whether an event is barred stays with the professional.

There is a full sample review at clause60.com/demo, with no sign-up needed.

This article is general guidance on the standard NEC3 and NEC4 forms, written from professional experience. It is not legal advice. Time-bar questions turn on the exact words of your contract and the facts, and where significant value is at stake you should take advice. NEC is a registered trade mark of its owner; Clause 60 Limited is not affiliated with or endorsed by NEC.