Modern slavery evidence for construction prequalification

A construction PQQ may ask for a modern slavery statement, policy or evidence of supply-chain controls. The first question is which request you are answering: a statutory obligation to publish an annual statement, a client procurement condition, or a question in a prequalification standard. A smaller supplier should not claim the same legal duty as a large commercial organisation simply because a tender form has a mandatory upload field.

This guide explains the distinction and the evidence a UK construction supplier can prepare. It does not replace legal advice on a particular group's turnover or business structure.

When is an annual statement legally required?

Section 54 of the Modern Slavery Act 2015 requires an in-scope commercial organisation carrying on business in the UK and supplying goods or services to prepare a statement for each financial year. The current prescribed turnover threshold is £36 million. The Home Office's practical guide explains how to assess scope, approve and sign the statement, and publish it.

The annual statement concerns the steps taken during that financial year to ensure slavery and human trafficking are not taking place in the organisation or supply chain, or states that no such steps were taken. Do not replace it with a generic assertion that the company is “fully compliant”. The law's publication duty is distinct from whatever additional evidence a buyer asks for in its procurement process.

A business below the threshold may still choose to set out anti-slavery arrangements, and a buyer may ask proportionate questions of its suppliers. That does not make the section 54 publication duty automatically apply to the smaller business. Where the application asks for a statutory statement you are not required to publish, explain that honestly and offer the relevant policy or process evidence if the buyer accepts it.

What does the Common Assessment Standard ask?

Build UK's Version 5 Common Assessment Standard (CAS) includes modern slavery questions in its corporate and professional standing section. Question 63 asks about an anti-slavery and human-trafficking statement or policy; question 64 asks how it is communicated to the workforce; question 65 asks whether the company ensures its supply chain is aware of, and abides by, the Modern Slavery Act. The question set includes conditional N/A instructions and marks question 65 advisory.

Use the current question set and your recognised assessment body's instructions. If you are not legally required to publish a statement, follow the question's N/A route where appropriate. Do not upload a statement borrowed from another company or relabel an unapproved draft as a board-approved annual statement. If you have a policy, show how it is communicated and used, rather than merely attaching a PDF.

Build a credible evidence pack

For an in-scope business, retain the applicable annual statement, approval and signature record, publication location and date, and the evidence behind the steps described. For any supplier, a buyer may find the following useful when proportionate to the work and supply-chain risk:

• a current policy or procedure with a named owner and approval date;
• worker and subcontractor communication or induction evidence;
• risk assessment of labour-supply and subcontracting arrangements;
• due-diligence questions asked of relevant suppliers and how answers are reviewed;
• a reporting route for concerns and records of action taken; and
• a process for updating the material when the supplier base or business changes.

These are examples of evidence, not a universal legal checklist. A small firm with no subcontractors may reasonably have a different pack from a labour-intensive national contractor. The buyer should ask for evidence that matches the actual procurement risk. The Home Office guide also makes clear that the published statement should reflect the organisation's real actions.

Avoid three common PQQ errors

First, do not confuse a modern slavery policy with the statutory annual statement. A policy sets out intended controls; a statement reports steps taken during a particular financial year. Second, do not assume a buyer cannot ask about modern slavery because your turnover is below £36 million; procurement questions and statutory publication duties are different. Third, do not claim that holding a CAS assessment or using software guarantees that no exploitation occurs in a supply chain.

For the wider assessment, read our CAS overview. If a buyer is evaluating contractor prequalification software, ask how it holds the statement, approvals, communication records and follow-up questions by supplier. Verify the workflow in a demonstration. Complys cannot determine the legal scope of section 54 or investigate exploitation on your behalf.

Sources and claim boundaries

• Modern Slavery Act 2015, section 54: the annual statement obligation.
• Home Office — Transparency in supply chains practical guide: current scope, approval and publication guidance.
• Build UK — Version 5 CAS question set: questions 63–65 and conditional evidence instructions.

Publication recheck: Reconfirm the threshold and the CAS version. Do not publish a fixed threshold or question number if the primary sources have changed by integration.