Subcontractors · Mandatory · Pre-Construction

Subcontractor Order and Work Package Brief

A brief setting out the scope of work, programme, access arrangements, design information, and H&S requirements for a subcontractor work package.

Last reviewed: 29 March 2026 — This guide reflects UK law as of this date. Contract Law remains current with no amendments enacted as of 29 March 2026. Next scheduled review: 29 March 2027.

Legal basis	Contract Law + CDM 2015 Reg 8
Purpose	The Work Package Brief (WPB) / Subcontractor Order defines: what the subcontractor is engaged to do; at what price; to what programme; in what location; to what quality standard; and under what health and safety obligations.
H&S content	The WPB must communicate the H&S obligations that apply to the subcontractor: site rules; permit to work requirements; CDM responsibilities; RAMS submission requirements; toolbox talk obligations; CSCS card requirements; reference to the Construction Phase Plan.
Back-to-back	The WPB should pass down the PC's obligations to the subcontractor. Key flow-down provisions: CDM 2015 compliance; H&S policy; insurance; HMRC CIS; Modern Slavery Act; drug and alcohol policy.
JCT/NEC	Many WPBs are issued under a standard form subcontract — JCT ICSub 2016, NEC4 Short Subcontract, or similar.

1. The Work Package Brief — Clarity Before Work Starts

The work package brief is the foundational commercial and contractual document for each subcontract package. It defines the scope of work, the price, the programme, and the obligations — and it does so in writing, before work commences. Subcontractors who begin work without a signed WPB are working under verbal agreement, which creates disputes about scope, price, and obligations that are extremely difficult to resolve.

The WPB also performs the CDM function of communicating health and safety obligations to the subcontractor before they mobilise. The reference to site rules, the Construction Phase Plan, permit to work requirements, and RAMS submission obligations ensures that the subcontractor cannot claim ignorance of their CDM responsibilities once on site.

Never allow a subcontractor to begin work without a signed order or WPB in place

Work begun without a signed order creates immediate commercial disputes when the subcontractor invoices for more than the PC expected, or when scope is disputed. The order must be agreed, signed, and in place BEFORE mobilisation.

2. Work Package Brief — Content

Section	Detail
Parties	PC name and address. Subcontractor name and address. Project name and address. Contract reference number.
Scope of works	Precise description of the works. Drawings and specifications that define the scope. Excluded items — what is NOT in scope.
Subcontract sum	Fixed price / schedule of rates / cost plus. Variations process. Payment terms.
Programme	Start date. Completion date. Key milestones. Attendance at progress meetings.
H&S obligations	CDM responsibilities. Site rules compliance. Construction Phase Plan access. RAMS submission requirements. PTW obligations. CSCS card requirements. Toolbox talk requirements.
Insurance	Required EL and PL cover levels. Provision of insurance certificates to PC before mobilisation.
CIS	CIS status as verified. Deduction rate confirmed.
Flow-down clauses	Modern Slavery Act. GDPR. Anti-bribery. Drug & alcohol policy.
Dispute resolution	Adjudication under Housing Grants Act 1996. Notice periods. Governing law.
Signatures	Both parties sign before work commences.

Common Mistakes

Allowing work to begin without a signed order

No signed order = verbal agreement. Verbal agreements about construction scope and price are extremely difficult to enforce and regularly result in expensive disputes.

WPB scope not matching what was tendered or agreed

The most common source of subcontract disputes is a mismatch between what the subcontractor priced and what the WPB says they must do. The scope in the WPB must exactly reflect what was agreed at tender.

No H&S obligations in the WPB

A WPB that covers scope, price, and programme but contains no health and safety obligations does not discharge the PC’s CDM duty to communicate H&S requirements. The H&S section of the WPB is not optional.

Payment terms that do not comply with the Housing Grants Act 1996

The Housing Grants, Construction and Regeneration Act 1996 (as amended) requires payment notices, pay-less notices, and adjudication rights in all construction contracts of 45+ days. A WPB that does not include these provisions must include the Scheme for Construction Contracts as the default.

Not flowing down CDM and compliance obligations to the subcontractor

A WPB that doesn’t explicitly pass down obligations means the subcontractor has no contractual obligation to comply with CDM, site rules, or RAMS requirements. Flow-down provisions must be explicit.

3. Frequently Asked Questions

What payment provisions are required under the Housing Grants Act?▾

The Housing Grants, Construction and Regeneration Act 1996 (as amended) requires: the right to payment in instalments (for work lasting more than 45 days); an adequate mechanism for determining when and what amounts are due; a right to suspend for non-payment (after notice); and adjudication as a 28-day dispute resolution mechanism.

What is a ‘back-to-back’ subcontract and why does it matter?▾

A back-to-back subcontract passes down obligations from the main contract to the subcontract. Without back-to-back provisions, the PC may be liable to the client for the subcontractor’s failure but have no contractual right to recover from the subcontractor.

Must the WPB be under a standard form contract?▾

There is no legal requirement to use a standard form contract (JCT, NEC, etc). However, standard forms provide proven legal frameworks for dispute resolution and industry-recognised provisions. For contracts above a modest value, a standard form subcontract provides significantly better protection for both parties.

What happens if a subcontractor starts work without returning the signed order?▾

Conduct can constitute acceptance of a contract — but this is a legally uncertain position. The practice of chasing for signed orders and not allowing mobilisation without them is significantly safer than relying on conduct.

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