The NEC4 suite of contracts covers works, services and supply, with full forms for complex jobs, short forms for simple ones and subcontracts to pass risk down the chain. The Engineering and Construction Contract (ECC) gets the most attention, but it is only one of the forms, and each form has its own roles, clause numbers and periods.
For background on the edition itself, see the NEC4 contracts guide. To choose between forms, go to choosing an NEC contract.
Works contracts
| Form | Use it for |
|---|---|
| Engineering and Construction Contract (ECC) | Building, infrastructure and process plant work, including any level of Contractor design. Has main Options A to F. |
| Engineering and Construction Subcontract (ECS) | Subcontracting works under an NEC4 main contract. Uses the ECC's clause numbers, with no Option F. |
| Engineering and Construction Short Contract (ECSC) | Simpler, lower-risk works. |
| Engineering and Construction Short Subcontract (ECSS) | Simple subcontract packages. |
| Design Build and Operate Contract (DBOC) | Works that continue into an operating phase with the same supplier. New in NEC4. |
| Alliance Contract (ALC) | Several parties delivering work as one integrated team, with shared risk and reward. New in NEC4. |
Service contracts
| Form | Use it for |
|---|---|
| Professional Service Contract (PSC) | Engineering, architecture, project management and consultancy. |
| Professional Service Subcontract (PSS) | Passing part of a professional service to a subconsultant. |
| Professional Service Short Contract (PSSC) | Smaller, simpler appointments. Numbered differently from the PSC, and with far fewer procedures. |
| Term Service Contract (TSC) | Maintaining or managing assets over a period, such as asset management and maintenance. |
| Term Service Subcontract (TSS) | Subcontracting term services. |
| Term Service Short Contract (TSSC) | Simple, low-risk term services. |
| Facilities Management Contract (FMC) | Services such as cleaning, catering, security and maintenance. NEC also lists a short version (FMSC). |
Supply contracts
| Form | Use it for |
|---|---|
| Supply Contract (SC) | High-value goods and related services, such as transformers, cranes or complex plant. |
| Supply Short Contract (SSC) | Lower-risk items, such as building materials and parts. It keeps the word "Purchaser" rather than "Client". |
Forms that sit around the others
| Form | Use it for |
|---|---|
| Framework Contract (FC) | Appointing suppliers to a framework, with work then called off under another NEC form. |
| Dispute Resolution Service Contract (DRSC) | Appointing an Adjudicator or similar. It replaces NEC3's Adjudicator's Contract. The W1 and W2 dispute Options refer to it directly. |
What the forms have in common
The NEC documents state that the NEC4 forms are consistent with each other, and that consistency is one of the suite's selling points. In practice it means:
- the same broad section order in the longer forms: general, responsibilities, time, quality, payment, compensation events, title, liabilities and insurance, termination;
- early warnings and compensation events in nearly every form, though the short forms have fewer steps;
- subcontracts that use the same clause numbers as their parent contracts, which lets you run back-to-back subcontracts.
Where the forms differ
Don't assume that a rule you know from the ECC carries across. Three examples:
| Topic | ECC | Another form |
|---|---|---|
| Time to notify a compensation event | 8 weeks | ECS: 7 weeks |
| Time to quote | 3 weeks | ECS: 2 weeks |
| Number of core compensation events | 21 | PSSC: 8 |
The roles also change. The PSC and TSC have a Service Manager, not a Project Manager. In the ECS, the Contractor does the Project Manager's and the Supervisor's jobs.
Picking the right form: a quick test
- Is it mainly a physical thing being built? ECC or ECSC. Subcontracting it? ECS or ECSS.
- Is it mainly advice or design? PSC or PSSC, with PSS for subconsultants.
- Is it a continuing service over a period? TSC or TSSC, or FMC for facilities services.
- Is it mainly goods? SC or SSC.
- Does the short form fit? Use a short form only if the work is simple and the risk is low. If you need to add many Z clauses to make it work, you probably wanted the longer form.
The NEC contract types section has a page on each form, and ECC vs ECSC covers the most common decision.
Related guides
- NEC4 Contracts: A Complete Guide
- NEC3 vs NEC4: The Main Differences
- Early Warnings: What Changed in NEC4
- Programme Changes in NEC4
- What Is NEC4?
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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.