Subcontractors · Mandatory · Pre-Construction
Modern Slavery and Anti-Bribery Declaration
A declaration confirming compliance with the Modern Slavery Act 2015 and anti-bribery legislation.
Last reviewed: 29 March 2026 — This guide reflects UK law as of this date. Modern Slavery Act 2015 remains current with no amendments enacted as of 29 March 2026. Next scheduled review: 29 March 2027.
| Legal basis | Modern Slavery Act 2015 (s.54) + Bribery Act 2010 |
| Modern Slavery Act s.54 | Commercial organisations with turnover ≥£36m must publish annual modern slavery statement. Construction is a high-risk sector. |
| Construction risk | Labour-intensive; reliance on agency/subcontracted labour; migrant workers; limited oversight of lower-tier subcontractors |
| Bribery Act 2010 | Section 7 corporate offence of failing to prevent bribery. Adequate procedures defence available. |
| TISC guidance 2025 | Updated Home Office guidance emphasises risk-based supply chain mapping and board-level accountability |
1. Modern Slavery & Anti-Bribery — Supply Chain Integrity
Construction supply chains are considered higher risk for modern slavery due to their labour-intensive nature, reliance on agency and subcontracted labour, prevalence of migrant workers, and limited oversight of lower-tier subcontractors. The subcontractor declaration is one element of the supply chain due diligence process.
The Modern Slavery Act 2015 s.54 requires commercial organisations with a global turnover of £36m or more to publish an annual statement setting out the steps taken to ensure modern slavery is not taking place in their business or supply chains. Even organisations below this threshold have a moral and reputational obligation to conduct due diligence.
The Bribery Act 2010 creates a corporate liability for failing to prevent bribery by an 'associated person' — which includes subcontractors. Section 7 provides a defence where the organisation can demonstrate it had adequate procedures in place to prevent bribery. Requiring anti-bribery declarations from subcontractors is one element of establishing this defence.
Due diligence, not guarantee
The subcontractor declaration is not a guarantee — it is evidence of due diligence in a risk-based approach.
2. Modern Slavery & Anti-Bribery Declaration — Content
| Field | Detail |
|---|---|
| Company details | Registered company name, trading name, Companies House number, registered address |
| Modern Slavery declaration | Declaration that the company is not engaged in, and takes steps to prevent, modern slavery in its business and supply chain |
| Modern Slavery Act s.54 statement | If turnover ≥£36m: confirmation that an annual modern slavery statement is published and link/reference provided |
| Anti-Bribery declaration | Declaration that the company has adequate anti-bribery procedures and does not engage in or tolerate bribery or corruption |
| GLAA licence | If the company provides labour or uses a labour provider: GLAA licence number and expiry, or confirmation that a GLAA-licensed provider is used |
| Signatory | Director-level signatory: full name, position, signature, and date |
3. Common Mistakes
Treating declaration as tick-box without underlying due diligence
A signed declaration is meaningless without genuine due diligence behind it. The PC must consider whether the subcontractor's workforce practices, pay arrangements, and supply chain management are consistent with the declaration. Red flags — such as workers not holding their own identity documents, excessive deductions from pay, or workers housed in employer-controlled accommodation — must be investigated regardless of what the declaration says.
Not requiring declarations from lower-tier subcontractors
Modern slavery risk is highest in lower tiers of the supply chain where oversight is weakest. Requiring declarations only from tier-one subcontractors misses the areas of greatest risk. The PC should require tier-one subcontractors to cascade the requirement to their own supply chain.
Not updating declarations annually
Declarations should be renewed annually. A declaration signed three years ago does not reflect current practices, policies, or personnel. Annual renewal ensures the subcontractor re-confirms their position and the PC maintains current records.
Not having an anti-bribery policy of the PC's own
Requiring anti-bribery declarations from subcontractors while having no anti-bribery policy internally is inconsistent and undermines the adequate procedures defence under the Bribery Act 2010 s.7. The PC must have its own anti-bribery policy, communicate it, and monitor compliance.
Not having a clear escalation process if a violation is suspected
If indicators of modern slavery or bribery are identified, there must be a documented escalation process. Workers and managers must know who to report to, how reports are handled, and what protections exist for whistleblowers. Without this, violations may go unreported.
4. Frequently Asked Questions
Who must publish a modern slavery statement under s.54?▾
Commercial organisations with a global turnover of £36m or more that carry on business, or part of a business, in the United Kingdom. The statement must be approved by the board and signed by a director. It must be published on the organisation’s website with a prominent link from the homepage.
What is the GLAA?▾
The Gangmasters and Labour Abuse Authority. The GLAA licenses labour providers in certain sectors and has broader labour market enforcement powers that extend to construction. If a subcontractor uses agency labour, the labour provider should hold a valid GLAA licence. Using an unlicensed labour provider is a criminal offence in regulated sectors.
What are adequate anti-bribery procedures?▾
The Ministry of Justice guidance sets out six principles: proportionate procedures; top-level commitment; risk assessment; due diligence; communication (including training); and monitoring and review. An organisation that can demonstrate it has implemented these six principles proportionately to its risk profile has the adequate procedures defence under Bribery Act 2010 s.7.
Can a subcontractor be terminated for a modern slavery breach?▾
Yes. The subcontract should include a termination right for breach of the modern slavery and anti-bribery clauses. This should be a material breach entitling the PC to terminate immediately without a cure period. The right must be expressly stated in the subcontract — implied terms may not be sufficient.
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