NEC4 is the fourth edition of the NEC suite of standard contracts, published in June 2017 for construction, professional services, term maintenance, supply and related work. So when someone asks "what is NEC4?", the short answer is a family of contracts, not one document, and the best known is the NEC4 Engineering and Construction Contract (ECC).
NEC is owned and developed by the Institution of Civil Engineers. This page is the quick definition; the NEC4 contracts guide has the full overview.
The key facts
| Published | June 2017 |
|---|---|
| Later amendments | January 2019, October 2020 and January 2023 for the ECC |
| Owner | Institution of Civil Engineers, through its NEC division |
| Previous edition | NEC3, published June 2005 and last reprinted with amendments in April 2013 |
| What it covers | Works, services and supply, in full and short forms, with subcontracts |
| Core idea | A contract that helps people manage a job as it happens, with set procedures for risk, change and programme |
What NEC4 was written to do
The foreword to the NEC4 documents gives three aims, which in our words are: encourage better management, support newer ways of procuring work, and take NEC into more markets and sectors. The contracts' owners present NEC4 as a development of NEC3 rather than a new start. Anyone who knows NEC3 will recognise most of it.
That shows in what's new. The suite gained a design, build and operate contract, a multi-party alliance contract and extra subcontract forms. Inside the contracts, parts of cost can now be finalised during the job, and a step involving the Parties themselves was added to the dispute process. The whole set was also made more consistent across its forms.
How it works day to day
Under the NEC4 ECC, four habits do most of the work:
- Warn early. Either side tells the other as soon as it knows of a matter that could affect cost, time or performance (15.1).
- Keep a live programme. The Contractor revises the programme for acceptance (32.2), and delay is measured against the Accepted Programme (63.5).
- Handle change as it happens. Compensation events are listed at 60.1(1) to 60.1(21) and are notified, quoted for and implemented during the job.
- Reply on time. Most replies have a period, and some late replies can be treated as acceptance.
Who uses NEC4?
Clients, project managers, contractors, consultants, subcontractors and suppliers across infrastructure, utilities, transport and building work use it. In the UK, the NEC4 documents carry a statement from the Government Construction Board, part of the Cabinet Office, recommending the contracts for public sector construction where they are appropriate. The same documents carry a statement from Hong Kong's Development Bureau about a gradual move to NEC4 on public works.
You will often meet NEC4 as a subcontractor or consultant to a larger client without having chosen it. In that case your form may be the Engineering and Construction Subcontract or the Professional Service Contract, and each has its own numbers and periods. The NEC4 suite page lists them all.
What NEC4 isn't
- It isn't a single contract. Saying "we're on NEC4" doesn't tell you the form or main Option. Ask for both.
- It isn't automatically the edition on your job. A contract stays on the edition it names, and NEC3 is still found on existing contracts and frameworks.
- It isn't a complete agreement off the shelf. The Contract Data, the Scope and any Z clauses make each contract its own.
- It isn't a rewrite of NEC3. Numbers moved and words changed, but the method stayed.
How to tell which edition you are on
- Open Contract Data part one. Its opening statement names the conditions of contract, including the edition.
- Check the date. NEC4 forms are dated June 2017 onwards, while NEC3 ECC is June 2005 or April 2013.
- Look at the words. "Client" and "Scope" point to NEC4; "Employer" and "Works Information" point to NEC3 ECC. Be careful with professional service contracts, because the NEC3 PSC already used "Scope".
- Look at the early warning clause. It is 15 in NEC4 ECC and 16 in NEC3 ECC.
Coming from the previous edition? NEC3 vs NEC4 compares the changes that matter.
Related guides
- NEC4 Contracts: A Complete Guide
- The NEC4 Suite of Contracts
- NEC3 vs NEC4: The Main Differences
- Early Warnings: What Changed in NEC4
See how this works in practice
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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.