These NEC4 questions and answers cover what teams most often ask when they first meet the edition or move across from NEC3. Each has a short answer and a link to more detail. The answers refer to the NEC4 Engineering and Construction Contract (ECC) unless we say otherwise, and your Z clauses and Contract Data can change them.
For a structured overview rather than a quick answer, read the NEC4 contracts guide.
Edition and forms
1. When was NEC4 published?
June 2017. The ECC was later amended in January 2019, October 2020 and January 2023, so check which version your contract names. See what NEC4 is.
2. Can we still use NEC3?
A contract let on NEC3 stays on NEC3 unless the Parties agree otherwise, and many frameworks and long contracts are still running on it. For a new job, the choice is the Client's. The NEC4 documents carry the UK Government Construction Board's recommendation favouring NEC4 for public sector work where appropriate. See whether NEC is mandatory.
3. Do clause numbers match between NEC3 and NEC4?
Many do, but a number of them moved. Early warnings went from 16 to 15, and implementing compensation events went from 65 to 66. The renumbering table lists the main moves.
4. Does the subcontract use the same numbers?
Yes, broadly. The ECS uses ECC numbers, with the Contractor in the Project Manager's and Supervisor's place. But the periods often differ: for example, 7 weeks rather than 8 to notify a compensation event. Definitions are numbered differently too.
Day-to-day procedures
5. How soon do early warning meetings start?
The Project Manager issues the first register within one week of the starting date and instructs the Contractor to attend a first meeting within two weeks of it (15.2). Later meetings can be called at any time, and take place at no longer than the Contract Data interval. See early warnings in NEC4.
6. Can a programme be deemed accepted?
Yes, in NEC4. The Project Manager has two weeks to answer. If there's no answer, the Contractor may notify the failure, and a further week of silence means the programme is treated as accepted (31.3). NEC3 has no such rule. See programme deemed acceptance.
7. What if the Contractor doesn't submit an application for payment?
The amount due becomes whichever is lower: the Project Manager's assessment or last time's amount due (50.4). So a missed application normally means no increase that month. See payment applications.
8. How many compensation events are there?
There are 21 core events, at 60.1(1) to 60.1(21). Options B and D add quantity-related events at 60.4 to 60.6, and some secondary Options add their own. The NEC4 compensation events list has them all.
9. Has the 8-week time bar changed?
No. In the ECC the Contractor still has 8 weeks from becoming aware of an event to notify it, unless the event is one the Project Manager should have notified (61.3). See clause 61.3.
Money and disputes
10. How many fee percentages are there?
One. NEC3's separate direct and subcontracted percentages are gone, and the Fee is calculated by applying a single percentage (11.2(10)). See cost and Fee changes in NEC4.
11. Is there a final account?
There is a final assessment rather than a traditional account. The Project Manager assesses the final amount due after the Defects Certificate, and it becomes conclusive unless a dispute is referred in time (clause 53). See the final assessment guide.
12. Do we have to negotiate before adjudicating?
It depends on the Option. Under W1, disputes go to Senior Representatives first. Under W2, for contracts where the UK Construction Act applies, that step is available if the Parties agree, and the right to adjudicate remains. See dispute resolution changes.
Quick reference
| Question | Short answer | Clause |
|---|---|---|
| Register first issued | 1 week from the starting date | 15.2 |
| Reply to a programme | 2 weeks, then 1 further week after notification | 31.3 |
| Notify a compensation event | 8 weeks from awareness | 61.3 |
| Quote for an event | 3 weeks | 62.3 |
| Reply to a quotation | 2 weeks, then 2 further weeks after notification | 62.3, 62.6 |
| Payment certificate | 1 week from the assessment date | 51.1 |
| Payment | 3 weeks from the assessment date, unless otherwise stated | 51.2 |
These are the standard ECC periods. Z clauses and other forms can differ, so check them against your contract. NEC time periods gives the longer list.
Related guides
- NEC4 Contracts: A Complete Guide
- What Is NEC3?
- NEC3 Contracts Explained
- NEC3 Main Options
- NEC4 Contract Data Explained
- Learning NEC4: What Your Team Needs to Know
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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.