What Is NEC3?

NEC3 is the third edition of the NEC suite of standard contracts, first published in June 2005. So the short answer to "what is NEC3?" is that it's the edition before NEC4, and still very much alive, since a contract stays on the edition it names and many long-running jobs and frameworks were let on it.

The best known form is the NEC3 Engineering and Construction Contract (ECC). The NEC4 contracts guide explains the current edition, and NEC3 contracts explained goes into more depth than this definition.

Key dates

Date	What happened
June 2005	Third edition published
June 2006	Reprinted with amendments
April 2013	Reprinted with amendments; this is the version most often quoted
June 2017	NEC4 published as its successor

The version date matters. A clause in a June 2005 contract could read differently from the April 2013 text. For example, the 2013 text changed clauses 61.1, 61.3 and 61.4. So find out which edition and amendment your own contract incorporates.

How NEC3 works

NEC3 uses the same method as NEC4. Early warnings come at clause 16, the programme at 31 and 32, compensation events at 60 to 65, and payment at 50 and 51. The Contractor has eight weeks from becoming aware of an event to notify it (61.3), and if the Project Manager doesn't reply to a notification or a quotation, the Contractor can notify the failure and treated acceptance can follow (61.4, 62.6).

The words differ from NEC4: the paying party is the Employer, the Contractor's requirements are the Works Information, the register is the Risk Register, and the Contractor is "he".

Why is it still in use?

• Contracts stay on their edition. A contract let on NEC3 keeps running on NEC3 unless the Parties formally change it.
• Frameworks last for years. Work called off late in a framework can still be on the form the framework set at the start.
• Clients have invested in it. Some have standard amendments and Z clauses, procedures and training built around NEC3.
• Disputes and final accounts run on. Even finished jobs may need NEC3 knowledge years later.

How NEC3 differs from NEC4

Topic	NEC3 ECC	NEC4 ECC
Paying party	Employer	Client
Requirements	Works Information	Scope
Early warnings	16, no set times	15, with set times
Programme with no reply	Compensation event, but no treated acceptance	Treated acceptance after a notification and a further week (31.3)
Core compensation events	19	21
Fee	Direct and subcontracted percentages	One percentage
End of the job	No final assessment clause	Clause 53

The full list is in NEC3 vs NEC4.

How to tell you are on NEC3

1. Look at Contract Data part one, where the opening statement names the conditions of contract and the edition.
2. Look for "Employer" and "Works Information". Be careful with professional services, as the NEC3 PSC uses "Employer" and "Scope".
3. Check whether the early warning clause is 16.
4. Check the Fee in part two. Two percentages suggest NEC3 ECC.
5. Watch for a mixture. A job could have an NEC3 main contract and an NEC4 appointment for a consultant, or the reverse, and each has to be run under its own rules.

What people get wrong

• Assuming it's out of date and so not binding. A later edition doesn't replace the terms of an existing contract.
• Applying NEC4 fixes. Telling an NEC3 Project Manager that a programme is now deemed accepted, based on NEC4's 31.3, has no contract basis without a Z clause.
• Using NEC4 templates. A notice that cites clause 15 on an NEC3 job points to the wrong clause.
• Treating every form as the same. NEC3 has its own suite, listed at NEC3 contracts explained, with different roles and periods in each.

Related guides

• NEC4 Contracts: A Complete Guide
• NEC3 Contracts Explained
• NEC3 Main Options
• Moving From NEC3 to NEC4
• Learning NEC4: What Your Team Needs to Know
• NEC4 Questions and Answers

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.