The critical difference lies not in the type of person supplied (manual worker vs. professional) but in the contractual relationship and scope of work being procured.
Key Differences in Contracting
The choice of NEC4 contract depends on the nature of the work the agency-supplied personnel are performing and the level of control the client has over them.
Professional Services Contract (PSC) (for Consultants/Professionals):
Scope of Work: The agency provides consultancy or management services (e.g., a project manager or engineer). The main output is advice, design, or project administration.
Control: The consultant generally has autonomy in deciding how to achieve the service objectives, reporting on progress and outcomes rather than being micro-managed day-to-day.
Contractual Status: The agency is a formal Consultant or Subconsultant under the PSC structure, taking responsibility for the specific service package they deliver.
Engineering and Construction Contract (ECC) or Term Service Contract (TSC) Context (for Manual Workers/Operatives):
Scope of Work: The agency provides physical labour (e.g., a bricklayer or electrician). The output is part of the physical construction or maintenance work itself.
Control: The manual workers typically work under the day-to-day supervision and direction of the main contractor, integrating directly into the contractor's existing team and processes.
Contractual Status: The agency is usually treated as a labour-only subcontractor or simply a supplier of "People" (labour) as a defined cost item, rather than a formal "Subcontractor" with responsibility for a distinct, defined part of the physical works.
How Manual Labour is Dealt with in the NEC4
When a recruitment agency supplies manual workers (operatives) for a construction project, the arrangement is usually handled in one of two ways:
1. Under the Main Contractor's ECC (as "People" costs)
If the main contractor is engaged with the client under an ECC contract, the cost of agency-supplied manual labour can be recovered as a "Defined Cost" under the Schedule of Cost Components (specifically, items related to People). The agency's role is essentially to provide the human resource, and they are paid based on agreed rates and actual time worked. The Project Manager can audit these costs.
2. Using a Supply Contract or Subcontract
The main contractor might have a call-off or framework agreement with the recruitment agency, which would typically be a NEC4 Supply Short Contract (SSC) for low-risk, standard supply of labour, or a simple commercial agreement. The payments from the contractor to the agency for manual workers are usually based on the agency's invoices, which cover the workers' pay, tax, NI, and the agency's margin.
Summary
The NEC4 Professional Service Contract is specifically designed for non-physical, professional consultancy roles. For the supply of manual workers carrying out physical construction operations, the work falls under the scope of a works contract (like the NEC4 Engineering and Construction Contract) or a related supply agreement, where the agency is treated as a supplier of labour rather than a professional consultant.