Defects Date Explained

The NEC defects date is the end of the period, set in the Contract Data, in which Defects are searched for and notified under the contract. It's explained here as a date in a sequence: it follows Completion of all the works, and it comes before or alongside the last defect correction period and the Defects Certificate.

It's worth having a clear picture of this sequence, since several rights and payments depend on it. For the meaning of the term on its own, see the defects date definition. For the overall process, see quality and Defects under NEC.

How the date is set

The Contract Data doesn't name a calendar date. It states how long after Completion of all the works the defects date falls. So the date is only fixed once Completion of the whole has actually happened and been certified.

Two points flow from this:

• If Completion is late, the defects date moves later as well.
• With sectional completion, an early section can sit in use for a long time before the defects date arrives, because the period runs from Completion of the whole. Clients and Contractors sometimes forget this when pricing.

Contract lengths vary, so check your Contract Data. There's no standard NEC period.

The sequence, with a worked example

A fictional hospital car park, with illustrative periods: a 52-week defects period, a 4-week defect correction period, and Completion certified on 2 March 2026.

Step	Date	What it means
Completion of the whole	2 March 2026	Periods start for Defects already notified
Barrier fault notified	19 January 2027	Correct by 16 February 2027
Lighting Defect notified	22 February 2027	Correct by 22 March 2027, after the defects date
Defects date	1 March 2027	The notifying and searching duties end
Lighting corrected	12 March 2027	All notified Defects are now corrected
Defects Certificate	Follows	Issued by the Supervisor
Final assessment	Within the stated time after the certificate	See the final assessment guide

A Defect notified one week before the date still gets the whole of its correction period. That's the reason a final inspection is best planned for a few weeks beforehand, so the results can be notified in time and the correction finished without any rush.

What ends at the defects date

Rule	NEC4 ECC	NEC3 ECC
The Supervisor's power to instruct a search	43.1	42.1
The duty on both sides to notify Defects as they're found	43.2	42.2
Certificates on each renewal of insurance (the submission duty runs until this date)	84.1	85.1
The access test for uncorrected Defects: access not given before this date	46.2	45.2

What doesn't end

• The Contractor's correction duty for Defects already notified. It carries on until the correction period ends.
• Insurance cover. The required cover keeps running until one of two certificates is issued (Defects or termination), which can be later. See insurance under NEC.
• The Client's rights over Defects not yet found. These survive even the certificate, under the general law.

Not the same as a defects liability period

People who have come from other forms often talk about a "defects liability period" or "rectification period". Under NEC, don't assume that the defects date is the end of liability. The defects date ends the notify-and-correct routine, not the Contractor's legal responsibility for hidden Defects. If you want an actual cut-off for liability, that's what the end of liability date in Option X18 is for.

Diary dates worth setting

1. The day Completion of the whole is certified: work out and publish the defects date.
2. Eight to twelve weeks before: plan the joint walk-round.
3. Four weeks before: notify anything found, and agree access.
4. On the date: check that the register has no unknown items.

These lead times are only suggestions. Set them to fit the size of the job and how long access takes to arrange.

Related guides

• Quality and Defects Under NEC
• The Defects Certificate Explained
• Keeping a Defects Register
• Quality Management Under NEC4
• Uncorrected Defects
• Accepting a Defect

This guide is general information in our own words, not legal advice. Your contract and its Contract Data always govern. NEC, NEC3 and NEC4 are trade marks of Thomas Telford Ltd; Contract Status is not affiliated with or endorsed by NEC.