With ESOS Phase 4 now underway, organisations across the UK are starting to ask the same questions: what’s changed, what do we need to do, and how can we stay compliant without unnecessary stress?
To help answer these questions, TEAM Energy recently hosted a live webinar, Navigating ESOS Phase 4, bringing together experienced practitioners and ESOS Lead Assessors to share practical advice, common pitfalls, and essential next steps. If you missed the session, you can watch the full webinar below.
Expert Guidance from ESOS Lead Assessors
The webinar was led by two of TEAM Energy’s seasoned ESOS Lead Assessors, Sam Arje and Tom McLeish, who collectively bring decades of experience supporting organisations through multiple phases of the Energy Savings Opportunity Scheme (ESOS).
Sam, one of the first accredited ESOS Lead Assessors in the UK, reassured that while Phase 4 introduces some refinements, the core compliance framework remains largely familiar. Tom echoed this, outlining that organisations should focus on improving energy audit quality, data accuracy, and action planning rather than expecting major structural changes.
From an organisational perspective, working with an experienced ESOS Lead Assessor can help turn compliance into a genuine value-driving exercise, unlocking cost savings, operational efficiencies, and long-term sustainability gains.
What’s New in ESOS Phase 4?
Although ESOS Phase 4 does not introduce sweeping legislative changes, the webinar highlighted several important developments that organisations must be aware of:
- Greater emphasis on audit quality
- Removal of simplified compliance routes, such as Display Energy Certificates
- Increased transparency, with more publicly available data
- Mandatory reporting on progress against previous action plans
A key takeaway is that ESOS is evolving beyond a ‘tick-box exercise.’ With enhanced scrutiny from the Environment Agency and a growing focus on net zero targets, businesses are expected to demonstrate genuine progress.
For many businesses, this means that the role of the ESOS Lead Assessor becomes even more important. Their expertise ensures audits are robust, compliant, and capable of delivering meaningful insights that stand up to regulatory scrutiny.
Why Early Preparation Matters
A consistent theme throughout the session was the importance of starting early. As demand for qualified ESOS Lead Assessors increases closer to the compliance deadline, organisations that delay risk:
- Limited availability of assessors
- Higher consultancy costs
- Increased likelihood of missing deadlines
Tom McLeish explained that early engagement allows businesses to plan site audits efficiently, minimise operational disruption, and begin implementing energy-saving measures sooner, delivering financial benefits well before submission deadlines.
Common Compliance Pitfalls to Avoid
Drawing on years of experience, Sam and Tom outlined some of the most frequent mistakes they have seen organisations make during ESOS compliance, including:
- Leaving preparation too late
- Failing to include all entities within a group structure
- Missing smaller energy streams or sites
- Over-reliance on estimated data
- Incomplete or non-representative site audits
These issues can lead to compliance failures, or worse, financial penalties. In fact, enforcement activity has increased, with significant fines issued by the Environment Agency to non-compliant organisations in recent years.
Working closely with an ESOS Lead Assessor from an early stage is one of the most effective ways to avoid these risks.
Action Plans and Ongoing Commitments
A major focus of Phase 4 is the continued emphasis on action plans and annual progress reporting. Organisations must not only identify energy saving opportunities but also demonstrate how they are progressing against them.
Importantly, even businesses that do not implement recommendations are still required to submit action plans and updates. This shift reflects ESOS’s growing role in driving accountability and transparency across UK organisations.
Looking Beyond Compliance
While ESOS remains a regulatory requirement, the webinar highlighted its broader value as a powerful strategic tool for internal change. Many of the recommendations identified through ESOS audits are low or no-cost actions, simple operational improvements that can deliver immediate savings.
Energy audits conducted by an ESOS Lead Assessor often uncover low cost or no cost efficiency improvements, such as operational changes or behavioural adjustments, that can deliver immediate savings. More complex investments, supported by clear payback data, can also help build strong business cases at board level.
As Sam Arje noted, ESOS is ultimately about reducing energy consumption, not just carbon emissions, making it a practical pathway to cost reduction as well as sustainability goals.
What’s Next?
With qualification assessments due by the end of 2026 and the main compliance deadline set for December 2027, organisations should already be reviewing their ESOS position.
Whether you’re preparing for your first submission or building on previous phases, expert guidance can make all the difference.
If you would like to learn more, watch the full webinar below or speak to one of our experienced ESOS Lead Assessors for tailored support.