ESOS Phase 4

ESOS audits to guide you through the compliance process. Create a plan that aligns with ESOS Phase 4

Who qualifies for ESOS and how do I comply?

ESOS Phase 4 applies to all large undertakings in the UK (businesses who employ more than 250 employees or who have an annual turnover of more than £44m and an annual balance sheet total in excess of £38 million). Organisations that qualify for ESOS must carry out energy assessments every four years, which audit their energy usage and identify cost-effective energy saving measures.

If you qualify for ESOS and your organisation is fully covered by ISO 50001 accreditation via a certified body, you still need to carry out an energy assessment. You will need to produce a summary report showing your organisation’s energy usage. However, you can use your existing ISO 50001 certification instead of having ESOS building audits carried out.

If you do not have an ISO 50001 energy management system or it only covers part of your energy use, you will need to carry out a full ESOS assessment. This will comprise the following steps:

Measuring total energy consumption and identifying areas of significant energy consumption
Ensuring areas of significant energy consumption are audited and compliant energy audit reports are produced
Appointing an accredited ESOS lead assessor to carry out, oversee and sign off the assessments, including board level director review and sign off.
Notify the relevant scheme regulator of compliance prior to the Phase 4 deadline (5 December 2027).

Talk to our experts

Kerry Moulds

Commercial Manager

kerry.moulds@socotec.co.uk 07779 131647

What is ESOS?

The Energy Savings Opportunity Scheme (ESOS) is a mandatory requirement and assessment scheme which encourages UK companies to measure and report on their energy use and efficiency, as well as identify opportunities to save energy. ESOS will consider an organisation’s entire energy usage across building/s, transport, industrial and commercial processes.

For organisations whose registered office is in England, ESOS compliance is regulated by the Environment Agency, which serves as the scheme administrator. Natural Resources Wales, Northern Ireland Environment Agency and Scottish Environment Protection Agency serve as the administrators for each of the respective countries in the UK.

When did ESOS start?

Having set out to reduce energy consumption by 20% by 2020, the UK government first introduced the ESOS scheme in 2014. ESOS was originally implemented in order to support businesses in overcoming information barriers that prevent them from investing in energy efficient measures. This is why organisations eligible for ESOS are required to carry out an energy audit every four years in line with each new phase.

ESOS Phase 4

How is ESOS phase 4 different to ESOS phase 3?

The good news is that many of the changes that were due to be implemented for Phase 4 have been postponed to Phase 5.

There is no mandatory net zero requirement for Phase 4 – although this can be included on a voluntary basis. Anyone that wishes to do this must follow the process set out in the recently introduced PAS 51215-1:2025.

Proposed changes to qualification thresholds for ESOS to align with Streamlined Energy and Carbon Reporting (SECR) requirements will also not be taken forward in Phase 4.

However, the following changes will be implemented for Phase 4:

Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as compliance routes
Progress against the Action Plan commitments are to be included in the ESOS assessment
Where Action Plan commitments have not been met, participants must provide an explanation
All other aspects from Phase 3 will still be required in Phase 4, including the energy intensity metrics.
The government’s ESOS scheme is now in Phase 4. Phases run every four years, with the deadline for ESOS phase 3 compliance having passed on 5 June 2024 (extended from 5 December 2023).

The good news is that many of the changes that were due to be implemented for Phase 4 have been postponed to Phase 5.

Proposed changes to qualification thresholds for ESOS to align with Streamlined Energy and Carbon Reporting (SECR) requirements will also not be taken forward in Phase 4.

However, the following changes will be implemented for Phase 4:

Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as compliance routes
Progress against the Action Plan commitments are to be included in the ESOS assessment
Where Action Plan commitments have not been met, participants must provide an explanation
All other aspects from Phase 3 will still be required in Phase 4, including the energy intensity metrics.
The government’s ESOS scheme is now in Phase 4. Phases run every four years, with the deadline for ESOS phase 3 compliance having passed on 5 June 2024 (extended from 5 December 2023).

Key dates for ESOS phase 4:

ESOS Phase 4 runs from 6 December 2023 until 5 December 2027
Qualification date – 31 December 2026 (when a company must assess whether they are in scope for ESOS 4)
Compliance date – 5 December 2027 (by which date an organisation must be compliant).

Prepare for ESOS Phase 4

Read our ESOS Phase 4 Fact Sheet

The government’s ESOS scheme is now in Phase 4. Phases run every four years, with the deadline for ESOS phase 3 compliance having passed on 5 June 2024 (extended from 5 December 2023).

What is energy efficiency?

Energy efficiency involves the use of less energy to perform an action. Being energy efficient allows businesses to reduce their carbon footprint and become more environmentally friendly, as well as reducing the amount of money spent on energy. Becoming more energy efficient does not necessarily mean replacing old equipment with new units. Introducing occupancy controls or a Building Management System may be a cheaper way to drive efficiency as certain equipment can be retrofitted with energy saving controls, such as Air Handling Units, boilers, inverter motors and drives.

ESOS Guidance

Understanding and meeting the requirements of the Energy Savings Opportunity Scheme (ESOS) can be a complex task. At SOCOTEC UK, we offer expert guidance and dedicated support to make ESOS compliance straightforward and effective.

Navigating ESOS with SOCOTEC

ESOS is a vital energy assessment scheme for large UK enterprises, designed to enhance energy efficiency and reduce carbon emissions. SOCOTEC UK is here to guide you through the ESOS process with confidence.

How SOCOTEC UK Can Assist

Regulatory Insight: Our consultants are experts in ESOS regulations and provide clear, practical advice on compliance obligations.
Thorough Audits: We conduct comprehensive energy audits using advanced methods to identify energy-saving opportunities tailored to your needs.
Data-driven Analysis: Leveraging sophisticated tools, we analyze energy usage data to pinpoint areas for improvement and cost savings.
Actionable Recommendations: Our reports are detailed yet accessible, offering practical recommendations to enhance energy performance and achieve savings.

How can SOCOTEC help?

With a wealth of experience in energy efficiency, SOCOTEC has a strong track record in delivering carbon consultancy, energy management, audits and ESOS assessments. Our lead assessors can deliver, oversee and approve your business’ audits to ensure you meet compliance with confidence.

As well as developing a compliance plan which fully conforms with ESOS requirements, we will identify appropriate milestones to ensure you meet compliance by 5 December 2027. We also offer an ESOS lead assessor consultation to identify the most appropriate compliance strategy for your business.