Source: https://www.quantsurv.com/library/jct-vs-nec Content format: Markdown version of the public page. Content reviewed: 2026-10-11 # JCT or NEC: what the difference means for your project JCT and NEC both get you paid, but they go wrong in different ways. Here is how each treats your money, your notices and your time limits. by [Jack Butler-Kettle]() ยท About 4 min readShare ## The answer Both JCT and NEC establish rights, obligations and procedures. Their approaches to change, payment, time and cost differ, so each party needs a routine based on the actual form and amendments. Notification rules are a critical difference, but neither family has one universal deadline. The full NEC subcontract normally uses 7 weeks, not the main contract's 8 weeks. Exceptions, amendments and the particular claim matter. Check JCT notice obligations and consequences against the signed form too. ## Key differences Scroll across to read all columns. JCT and NEC4 compared | Feature | JCT | NEC4 | | --- | --- | --- | | Published by | The Joint Contracts Tribunal | The Institution of Civil Engineers | | Used most on | Building work | Infrastructure and public sector work | | Contract forms | Building contracts including Standard Building and Design and Build, with separate subcontract forms | Engineering and Construction Contract (ECC), subcontract (ECS) and short forms | | How the price works | Depends on the form; lump sum, measurement and target cost forms exist | ECC offers Options A to F; ECS offers A to E; short forms differ | | A change | A Variation, valued under the valuation rules | A qualifying compensation event, assessed using the applicable cost and Fee rules or permitted alternative basis | | Delay | Time and money are separate: Relevant Events and Relevant Matters | One compensation event deals with both time and money | | Notice time limits | Check the form, type of claim and amendments | Commonly 8 weeks in ECC and 7 in ECS; check the form, exceptions and amendments | | Payment | The selected form's application, valuation, notice and payment dates | The actual form's assessment and payment provisions, including applicable UK payment terms | | Risk added by | A schedule of amendments | Z clauses | ### JCT and NEC side by side These are broad distinctions between commonly used forms, not rules for every contract in either family. Check the edition, options and amendments. ### Check the right notice and deadline An NEC compensation event notice and an early warning perform different jobs. Missing a notification time bar can remove entitlement, subject to its exceptions. Missing an early warning can affect assessment. Do not assume a main-contract deadline applies to your contract. So on an NEC job, a register of every event and its deadlines is not just paperwork, because it is your money. See [changes and compensation events](). JCT notices also matter, including applicable early-notification provisions in 2024 forms. The consequence of a missed notice depends on the actual wording, type of claim and amendments. See [changes to your contract work](). ### Payment and cash flow Where [the Housing Grants, Construction and Regeneration Act 1996]() applies, its payment requirements must be met. Check the operations, jurisdiction and exclusions. The contract family alone does not establish statutory coverage. Read the actual payment and valuation terms in either family. JCT mechanisms depend on the form and pricing basis. The full NEC Engineering and Construction Subcontract offers completed-activity, measured and cost-based approaches. Check the applicable Defined Cost, Fee, disallowed-cost rules and other adjustments. Short forms differ. Keep assessment dates, applications, notices and actual cash receipts separate. ### Is one better for your project? Neither is better on its own. What decides your risk is how each has been amended: the schedule of amendments on JCT, and the Z clauses on NEC. Whichever form you are sent, ask the same three questions. When will you be paid? What notices must you give, and by when? What can be deducted from you? For more on each, read [What is a JCT contract?]() and [What is an NEC contract?](). If an amendment's meaning in law is unclear, ask your solicitor. A [Construction contract review before signing]() considers the actual package and amendments, rather than relying on the reputation of a contract family. ## Example ### The facts A plumber is asked to move the same pipe on two different jobs: one uses a JCT subcontract and the other an NEC subcontract. ### What happens 1. For each job, the plumber saves the instruction and records what changed from the agreed work. 2. On the JCT job, they check the variation and any separate time or loss-and-expense provisions. 3. On the NEC job, they check the compensation-event procedure for both price and time, using that subcontract's deadlines and cost rules. ### What this shows The physical change is similar, but the notices and assessment can differ. The signed terms decide the process on each job. ## Sources 1. [Housing Grants, Construction and Regeneration Act 1996, Part II (Construction contracts), as amended by the Local Democracy, Economic Development and Construction Act 2009, Part 8](). legislation.gov.uk. [Browse the Library]()