ACI Reports supports clients through the entire ESOS compliance process, ensuring a smarter approach to energy.
Through meaningful partnerships built on trust, we can help clients maximise the benefits of the Energy Savings Opportunity Scheme (ESOS).
Important Updates to ESOS
The government’s Energy Savings Opportunity Scheme (ESOS) has now entered Phase 4, running from 6th December 2023 to 5th December 2027. While several updates were planned, most major changes have been postponed to Phase 5.
For Phase 4, there is now no mandatory net zero requirement, though organisations may choose to include one voluntarily by following PAS 51215-1:2025. Proposed adjustments to align ESOS qualification thresholds with Streamlined Energy and Carbon Reporting (SECR) will also be delayed until the next phase.
The following updates do apply for Phase 4:
- Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as compliance routes
- Inclusion of progress against Action Plan commitments in each ESOS assessment
- Explanation required where Action Plan commitments have not been met
- Continuation of all Phase 3 requirements, including energy intensity metrics
(Note: The Phase 3 compliance deadline was 5 June 2024, extended from 5 December 2023.)
Navigating the Energy Savings Opportunity Scheme (ESOS) can be challenging. At ACI Reports, we provide expert advice and hands-on support to make achieving ESOS compliance simple and effective.
Our ESOS Review & ESOS Consultancy Services
Organisations that qualify for but do not comply with ESOS face fines reaching £90k or more. With ACI Reports, clients are supported from end to end with reliable, accurate, and impartial ESOS reporting and guidance. Our accredited energy assessors are strategically located across the UK, delivering fast turnaround to ensure ESOS compliance for a wide client base.
Following an initial consultation, we promote a “least cost” approach to ESOS. We will provide a roadmap to success, overseeing optimal strategies and preparing final reports for sign-off by our qualified personnel. Final ESOS reports are tailored to the unique needs of each client, including specific recommendations to help achieve tangible cost savings.
ESOS Phase 3 to Phase 4 Compliance
We are currently in Phase 4 of ESOS.
Ongoing requirements from Phase 3 include:
- Appoint a qualified ESOS Lead Assessor to carry out, oversee, and sign off ESOS reviews
- Measure at least 95% of the organisation’s total energy consumption over a 12-month period
- Calculate energy intensity ratios for buildings, transport, plant, and industrial processes
- Provide evidence that all reported data accurately represents the organisation’s energy use
- Identify energy-saving opportunities and develop plans for implementation over the next 4 years
- Produce an ESOS report, including any alternative compliance routes, such as ISO 50001
- Submit an Action Plan within 12 months of the end of the relevant compliance period
- Provide an annual Progress Report outlining progress against Action Plan commitments
New or updated requirements for Phase 4:
- Assessments carried out in Phase 4 must explicitly record progress against previously submitted Action Plan commitments (including Phase 3 Action Plans)
- Provide an explanation for why any commitments have not been met
- Note that Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) can no longer be used as compliance routes
The Environment Agency will publicly disclose ESOS data, including each organisation’s compliance notification, Action Plan, and Progress Reports. ACI Reports ensures all client submissions are clear, professional, and fully compliant for public release.
What Is ESOS?
As the UK continues to work towards its 2050 net zero goal, the Energy Savings Opportunity Scheme (ESOS) remains a key driver in helping large organisations identify and implement energy-saving measures.
Now in Phase 4, the mandatory scheme requires qualifying businesses to complete an ESOS review (also referred to as an ESOS survey or ESOS audit) every four years, accompanied by cost-effective recommendations to improve energy efficiency and reduce consumption.
ESOS currently applies to organisations with more than 250 employees or an annual turnover above £44.1million ($50 million). While SMEs remain exempt, future phases are expected to align thresholds with SECR requirements – potentially bringing more businesses into scope.
Key Dates for ESOS Phase 4
- Phase duration: 6th December 2023 – 5th December 2027
- Qualification date: 31st December 2026 (the date by which businesses must determine if they fall within the scope of ESOS Phase 4)
- Compliance deadline: 5th December 2027 (the date by which businesses must achieve full compliance)
Get Full Support Around ESOS Compliance with ACI Reports
ACI Reports is an independent building compliance consultancy. As we are not linked to any energy supplier, clients can be assured they will be supported with unbiased expertise regarding the Energy Savings Opportunity Scheme (ESOS).
Our ESOS consultancy and survey specialists will assist clients with the registration process right through to submission, helping you to:
- Improve energy management
- Enhance your reputation
- Reduce your carbon footprint
- Identify cost-saving opportunities
- Meet compliance obligations
- Achieve energy objectives
Our experienced team delivers huge added value for clients through legislation interpretation, governmental reporting, and end-to-end project management. If you are looking for ESOS guidance or wish to discuss your requirements in more detail, please get in touch.
ACI Reports has a team of experienced energy assessors ready to support your organisation with ESOS compliance. Get in touch for a quotation!
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Frequently Asked Questions
What phase of ESOS are we currently in?
The UK is now in Phase 4 of ESOS, following the completion of Phase 3 submissions in June 2024. Officially, Phase 4 will run from 6th December 2023 to 5th December 2027, with compliance deadlines and reporting requirements to be confirmed by the Environment Agency.
What was the deadline for ESOS phase 3 compliance?
The deadline for submitting a Phase 3 notification of compliance was 5th June 2024. Organisations that qualified for Phase 3 but failed to submit their notification are at risk of enforcement action and should contact the Environment Agency immediately.
What is an ESOS assessment?
An ESOS assessment, or ESOS review, is an energy audit designed to measure how your organisation uses energy and identify opportunities to improve efficiency. It covers buildings, industrial processes, and transport. A qualified Lead Assessor reviews your data and verifies your findings before submission to the Environment Agency.
How do you complete an ESOS assessment?
Completing an ESOS assessment involves several technical and reporting steps. Many organisations choose to use a specialist provider – such as ACI Reports – to manage the entire process from start to finish.
The main steps are:
- Determine if your organisation qualifies based on its size and activities
- Measure your total energy consumption across buildings, industrial processes, and transport
- Identify areas of significant energy use that together account for at least 95% of your total energy consumption
- Carry out detailed energy audits (or use an approved alternative such as ISO 50001 certification) to identify opportunities for energy savings
- Appoint an approved ESOS Lead Assessor to review, validate, and sign off your assessment
- Submit your notification of compliance through the Manage your ESOS reporting system
Engaging a qualified Lead Assessor early allows your chosen provider to oversee every stage efficiently and ensure nothing is missed before submission.
How much does an ESOS assessment cost?
The cost of an ESOS assessment varies depending on the size, complexity, and number of sites within your organisation. While the assessment involves upfront costs, most participants find the financial savings from implementing recommendations significantly outweigh compliance costs.
How often do you need to report ESOS?
ESOS operates in four-year compliance cycles. If you submitted a notification of compliance for Phase 3 (deadline: 5th June 2024), you must also submit:
- An Action Plan by 5th December 2024 (now past due, but was still accepted until 5th March 2025)
- Annual progress updates in the following two years
If your organisation did not qualify for Phase 3, you are not required to complete an Action Plan or progress updates in the next phase.
How do annual progress updates work?
After submitting your Action Plan, you must file two annual progress updates detailing progress against your energy-saving commitments.
For Phase 3:
- First progress update: due 5 December 2025
- Second progress update: due 5 December 2026
Each update must be approved by a board-level director and submitted via the Manage your ESOS reporting system.