ESOS Phase 4: What's Changing and How to Prepare

By Dan Ellis, ESG Service Line Director

Key Takeaways

• ESOS Phase 4 places greater emphasis on action, including progress against commitments made in Phase 3 Action Plans.
• Organisations should be prepared to explain measures that were delayed, changed or not implemented and maintain a clear audit trail of those decisions.
• Preparing ahead of the 2027 compliance deadline can help businesses track progress, improve energy data and incorporate ESOS into wider investment planning.

NORTHAMPTON, MA / ACCESS Newswire / October 6, 2026 / With the Energy Savings Opportunity Scheme (ESOS) qualification date set for 31st December 2026, many organisations are beginning to turn their attention to Phase 4. While the scheme isn't undergoing a dramatic transformation, there are some important changes that signal a clear shift in direction.

The biggest message from the Government and regulators is simple. ESOS Phase 4 is not only about identifying energy-saving opportunities but also about demonstrating action.

For organisations that qualified for Phase 3, now is the ideal time to understand what Phase 4 will require and start preparing accordingly.

Phase 3 introduced some of the most significant changes ESOS has seen since its launch. Businesses were required not only to complete ESOS energy audits and submit a Notification of Compliance but also to produce an Action Plan, commit to implementation timelines, report publicly on proposed energy-saving measures and submit annual Progress Updates following compliance.

These changes were designed to move ESOS beyond a simple audit exercise and encourage the implementation of energy efficiency measures.

What is Changing for ESOS Phase 4?

1. Greater Focus on ESOS Action Plan Delivery

Perhaps the most important change is that organisations will be expected to report against the commitments they made during Phase 3.

The Government has indicated that progress against Action Plan commitments should be included within the Phase 4 ESOS assessment itself. This means businesses should already be tracking:

• Which projects have been completed
• Which remain in progress
• What energy and cost savings have been achieved
• What barriers have prevented implementation

For many organisations, this will be the first time ESOS compliance directly reflects what happened after the audit.

2. Explaining Why Measures Were Not Implemented

ESOS has never mandated that organisations implement audit recommendations.

However, Phase 4 is expected to require participants to explain where Action Plan commitments have not been delivered. However, this doesn't mean businesses will be penalised for not proceeding with every recommendation.

What it does mean is that organisations should be able to demonstrate clear decision-making and maintain an audit trail explaining why projects were delayed, changed or cancelled.

3. Removal of DEC and GDA Compliance Routes

Another notable change is the planned removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as ESOS compliance routes.

For some organisations this may have little impact. For others, particularly those relying on these routes to reduce audit requirements, it could result in additional site assessments or greater reliance on ISO 50001 certification.

What Isn't Changing for ESOS Phase 4?

There has been a lot of discussion in recent years about broadening ESOS to cover wider decarbonisation and net zero requirements. For now, that has been postponed. The Government has confirmed that proposed net zero-focused changes will not be introduced until Phase 5. ESOS qualification thresholds are also expected to remain unchanged for Phase 4.

This means businesses can continue preparing based on the existing framework while keeping an eye on future developments.

However, some ESOS Lead Assessors are also GHG auditors and decarbonisation experts and may include carbon reduction plans as a standard part of ESOS energy audits. This allows organisations to get extra value from the energy audit process and use data for other purposes, such as tracking progress against Science-Based Targets.

How Should Businesses Prepare for ESOS Phase 4?

Although the Phase 4 compliance deadline in December 2027 feels a long way off, the organisations that get most value from ESOS rarely wait until the final year. Five practical steps can help businesses prepare:

• Review your Phase 3 Action Plan
• Track implementation of committed measures
• Quantify energy and cost savings achieved
• Improve energy data management processes
• Build ESOS requirements into capital investment planning

Early planning should also account for the costs and resources associated with ESOS compliance. If you cannot demonstrate what happened to the recommendations identified in your previous audits, compliance is likely to become more difficult and more time-consuming.

ESOS Phase 4: From Compliance to Energy-Saving Action

Too often, ESOS is viewed as a regulatory burden. Yet every phase continues to reveal significant opportunities for organisations to reduce energy consumption, strengthen operational resilience and lower costs.

The direction of travel from Government is increasingly clear. Businesses are being encouraged not just to identify energy-saving opportunities but to demonstrate tangible actions.

Those organisations that embrace this approach early will not only find Phase 4 easier to manage but will also be far more likely to capture the substantial financial savings that effective energy management can deliver.

Start Preparing for ESOS Phase 4

Preparing early can give organisations more time to complete energy audits, address data gaps and plan for Phase 4 requirements before the compliance deadline.

Learn more about Antea Group's ESOS compliance services and how our ESOS Lead Assessors can support your organisation through Phase 4.

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Contact Info:
Spokesperson: Antea Group UK
Website: https://www.3blmedia.com/profiles/antea-group-uk
Email: [email protected]

SOURCE: Antea Group UK