Who’s Liable for Subcontractor Safety? You Might Be

UK legislation requires main contractors to review the necessary information, instruction and training; and the right level of supervision on sites. Digital systems like HSI Skillko help you manage it. 

Who is responsible for subcontractor safety?  

The main contractor always holds primary responsibility for site safety. Even when tasks are delegated to subcontractors, your duty under CDM 2015 and the Health and Safety at Work etc. Act remains in force. The HSE is explicit: if you're the client or main contractor, you must ensure all workers are trained, competent, and properly managed. 

Control is the test. If you set the schedule, determine the method of work, or manage site access, you hold the risk, even if you’re not the one doing the work. The HSE notes that contractors and subcontractors also carry duties, but these do not remove the overarching responsibility from the principal contractor. 

But knowing you’re responsible isn’t enough. The next step is understanding what the HSE actually expects you to do about it. 

Where does the safety gap usually form? 

The gap forms between procurement and site management. Here’s how it usually happens: 

• A contractor is approved at the procurement level based on company credentials. 
• Their workers arrive on site with no individual vetting.
• The site team assumes vetting was done upstream.
• Training gaps, expired certs, or unfamiliarity with site-specific rules go unnoticed. 

To fix this, you need verifiable proof that workers are trained and qualified before they touch the job. Regulators and insurers demand it. 

What other proof is expected?   

Signed paper forms aren’t enough. You need real-time compliance records. The HSE’s CDM guidance (L153) makes clear that principal contractors must demonstrate role-based training, inductions, and competence management throughout the project. 

Insurers now request the same. The Association of British Insurers notes that insurers expect evidence of sound health and safety management and may adjust premiums if it’s lacking. The Get It Right Initiative’s Insurance Guide reinforces that strong risk management and documented controls reduce both risk and costs. These expectations are grounded in the reality that workplace incidents still cost lives and money, as seen in official HSE health and safety statistics. 

Meeting that standard takes systems built for live tracking, not static forms. Platforms like HSI Skillko allow you to meet these expectations with auditable digital records, which are much harder to dispute in court than spreadsheets or manual files. The next section shows how to build that kind of system. 

How do you integrate subcontractors into your safety system?  

Here’s what a digital-first contractor compliance setup looks like: 

• Contractor registers through your portal with business and worker-level data.
• Skill requirements are assigned by task, e.g., confined space, first aid, abrasive wheels. 
• Workers complete eLearning or upload records for verification.
• Photo ID and digital sign-off confirm attendance and authorisation.
• System tracks refreshers and flags non-compliance automatically. 
  

This doesn’t replace supervision, but it empowers it. Site managers see the same data as the safety team, which keeps enforcement consistent. The HSE’s induction guidance, competence framework, and contractor responsibilities under CDM all align with this system-driven approach.  

Of course, building this yourself is hard. That’s where HSI Skillko’s automation tools come in.  

How do you integrate subcontractors into your safety system?

HSI Skillko centralises all safety management data into one system, live and accessible. HSI Skillko’s compliance automation tools let you: 

• Prequalify subcontractors based on role, client, and regulatory requirements. 
• Assign specific training and onboarding paths for each subcontractor by task. 
  
• Use photo ID and digital signature tools to verify who’s on site and what they’ve completed.
• Track training expiry and competency gaps in real time, not just at hire.
• Run audits instantly, across employees and the supply chain. 

Compliance isn't just about ticking boxes, it’s about controlling risk you can’t afford to ignore. HSI Skillko lets you stop guessing and start verifying. If a subcontractor is on your site, your name is accountable. Make sure you can prove they’re ready to work safely. 

Ready to centralise subcontractor safety and training? Book a HSI Skillko demo and bring all your workers under one source of truth  

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