Energy Savings Opportunity Scheme

ESOS Consultancy Services

Ensure compliance and identify energy saving opportunities
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What is The Energy Savings Opportunity Scheme?

The Energy Savings Opportunity Scheme (ESOS) is an energy assessment and energy saving scheme for large organisations. More than a compliance exercise, ESOS helps businesses understand how energy is used across their operations, identify opportunities to reduce energy consumption and costs and support wider sustainability and carbon reduction objectives.

You must participate in ESOS if your organisation, or any UK undertakings in your organisation’s group, qualifies as a large undertaking if, on 31 December 2026, it:

employs 250 or more people, or
has an annual turnover in excess of £44 million, and an annual balance sheet total in excess of £38 million

Administered by the Environment Agency, ESOS requires organisations to conduct an ESOS assessment and report compliance every four years, along with an Action Plan and Annual Progress Updates.

While ESOS is separate from the Streamlined Energy and Carbon Reporting (SECR) framework, many organisations are subject to both schemes and can benefit from a coordinated approach to energy management, reporting and carbon reduction.

With ESOS Phase 4 qualification assessed on 31 December 2026, early preparation can reduce compliance costs, improve data quality and provide more time to identify and implement energy-saving opportunities.

At Teamwork IMS, we provide end-to-end ESOS support, from compliance assessments and energy audits through to Action Plans and annual progress updates. Our experienced consultants help organisations achieve compliance efficiently while identifying practical opportunities to reduce energy costs, improve performance and generate long-term business value.

ESOS Phase 4: Key Changes You Need to Know 

ESOS Phase 4 is raising the bar on accountability and action, shifting the focus from simply identifying opportunities to demonstrating implementation and measurable energy savings. 

Key changes include: 

✅ Demonstrate progress against previous ESOS commitments 
✅ Mandatory Action Plan Reviews for measures not implemented 
✅ Report energy savings achieved and measures delivered 
✅ Enhanced evidence, calculation and reporting requirements 
✅ DECs and GDAs removed as standalone compliance routes 
✅ Additional reporting requirements for ISO 50001 and audit coverage 
✅ Increased focus on implementation, not just identifying opportunities 

How it can make a difference to your organisation

Improved Energy Management

Our specialist ESOS consultants can help your organisation identify energy-saving opportunities to reduce energy consumption and costs, improving environmental performance

Customer Confidence

Enhance your reputation by demonstrating your responsibility for combatting climate change by saving energy and reducing emissions

Carbon Footprint

Our ESOS consultancy and advice can help reduce your carbon emissions and support your carbon reduction plans on a pathway footprint through energy efficiency

Reduced Operational Costs

Our ESOS Assessments will identify areas you can improve energy efficiency, reduce energy consumption an resource costs

Regulatory Compliance

ESOS Assessments, approved by an ESOS Lead Assessor, will ensure you are compliant with current ESOS regulations and can support other sustainability obligations (e.g. SECR)

Complete Framework

Provides a framework to achieve your energy goals, which in turn improves energy efficiency, reduces costs and strengthens resilience against future energy and climate-related risks

Our ESOS Compliance Lifecycle

Scoping

We will clarify your ESOS obligations, define the reporting scope, review available data and agree on audit timelines and performance indicators

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Energy Audits & Data Gathering

We will carry out site audits, validate energy sources and guide you on the data needed to identify energy-saving opportunities

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ESOS Report & Energy Saving Opportunities

We’ll deliver a compliant ESOS report with detailed site surveys, data analysis and prioritised energy-saving recommendations, including cost and payback insights

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Environment Agency submission

Our ESOS Lead Assessor will sign off your report and support submission through the MESOS portal to ensure full compliance

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Energy Action Plan & Annual Progress Updates

We can help you identify action plan commitments to reduce energy consumption and produce the required 4-year action plan for ESOS phase 4, along with supporting the submission. We’ll then work with you each year to update your progress, including estimated energy and cost savings

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Why choose Teamwork IMS?

Experienced Professionals

Teamwork IMS is a leading provider of Compliance and Sustainability solutions to a wide range of business sectors worldwide. Our solutions support compliance, expedite ISO certification, promote sustainability and drive improvement initiatives. Our team of professionals includes MBCI, GDPR, ISEP, ESOS and ISO Lead assessor, CMIOSH, , CISSP, PCI Security Standards Council QSA qualified consultants.

Multi-disciplinary team

Our knowledge and experience across a broad base of management and technical Standards make us uniquely equipped to help organisations to comply with sustainability requirements and integrate these with existing management systems to achieve significant savings and efficiencies.

Part of your business

The continued success of both the project delivery and maintenance phases of our Compliance and Sustainability programmes is built on two key principles:

– The exceptional insight of our consultants, who consistently go beyond the Standards and services to identify, define, and align with the core business drivers that truly matter to our clients
– Our unique ability to integrate effortlessly with our clients’ teams, fostering collaboration and trust, and becoming a valued extension of their operations.

Global credentials

Our consultants have developed and successfully led IAF National accredited ISO and other Standards-based and sustainability improvement programmes for private and public-sector organisations across an international client base.

How Can Teamwork Help?

Our experienced ESOS Lead Assessors help organisations achieve compliance, improve energy performance and identify practical cost-saving opportunities. From Energy Audits and Action Plans to Annual Progress Updates, we provide expert support throughout the ESOS process.

Our ESOS Lead Assessors can help you:

✅ Achieve full ESOS compliance with confidence
✅ Identify realistic opportunities to reduce energy costs
✅ Demonstrate progress against previous commitments
✅ Align ESOS with wider sustainability and carbon reduction programmes
✅ Develop practical Action Plans that deliver measurable savings

Speak to one of our ESOS consultants today to discuss your compliance requirements, energy audits, Action Plans and opportunities to reduce energy costs.

Related Standards and Services

Frequently asked questions

Does ESOS apply to my organisation?

Your organisation must participate in ESOS (Energy Savings Opportunity Scheme) if, on the qualification date of 31 December 2026, it qualifies as a large undertaking or is part of a corporate group that includes a large undertaking.

An organisation is considered a large undertaking if it meets either of the following criteria:

Employs 250 or more people; or
Has an annual turnover of more than £44 million and an annual balance sheet total exceeding £38 million.

To determine whether you qualify, you should use the employee numbers, turnover, and balance sheet figures from the financial year ending either:

On 31 December 2026; or
Within the 12 months immediately preceding 31 December 2026.

If your organisation forms part of a group, the qualification assessment must be carried out for each individual undertaking within the group. Even where consolidated accounts are used for reporting purposes, a subsidiary or individual undertaking may still qualify as a large undertaking in its own right and therefore bring the group into ESOS compliance.

Not sure if ESOS applies to your organisation? We can help you assess your eligibility and identify your compliance obligations.

Do we need to comply with ESOS if we are ISO 50001 certified?

Yes, ISO 50001 certification can be used as a route to ESOS compliance, provided your certified Energy Management System covers all energy consumption within the scope of ESOS across your UK group and remains valid on the ESOS compliance deadline.

Where a fully compliant ISO 50001 Energy Management System is in place, it effectively replaces the requirement for ESOS energy audits and you do not need an ESOS Lead Assessor to review your compliance.

To qualify, your ISO 50001 certification must be issued by an accredited certification body, such as:

a UKAS accredited certification body
a body accredited by an EU member state’s national accreditation body
a body accredited by a member of the International Accreditation Forum

Even when using ISO 50001 as your route to compliance, you must still:

Calculate your total energy consumption and energy intensity ratios.
Calculate and report energy savings achieved since the previous ESOS compliance period.
Prepare and maintain an ESOS report.
Share relevant ESOS compliance information across applicable group undertakings.
Obtain Board-level approval confirming that:
- the organisation is ESOS compliant;
- the findings of the ISO 50001 system have been reviewed; and
- the information submitted within the compliance notification is accurate.
- Submit an ESOS compliance notification to the Environment Agency.
- Prepare an ESOS Action Plan and submit subsequent Annual Progress Updates.
- Maintain an evidence pack to demonstrate compliance.

Many of these requirements align naturally with an effective ISO 50001 management system, making compliance more streamlined while supporting continual energy performance improvement.

Beyond meeting ESOS requirements, ISO 50001 provides a structured framework for managing energy performance, reducing costs, identifying savings opportunities, and demonstrating a long-term commitment to energy management. It can also simplify future ESOS compliance cycles by integrating regulatory requirements into your existing management system.

Teamwork can help assess whether ISO 50001 is the right route for your organisation and ensure your management system is aligned with ESOS reporting, Action Plan, and Annual Progress Update requirements.

What is involved in the ESOS assessment process?

Organisations that qualify for ESOS must complete an assessment to understand how energy is used across their operations, identify opportunities for improvement, and demonstrate compliance with the scheme requirements.

The ESOS assessment process typically includes:

Calculating your total energy consumption across buildings, transport, and industrial processes
Identifying your areas of significant energy consumption (if relevant)
Calculating energy intensity ratios to measure energy performance.
Determining the most appropriate route(s) to compliance, such as ESOS energy audits or ISO 50001 certification,
Ensuring all significant energy consumption is covered by an approved compliance route.
Appointing an ESOS Lead Assessor, unless exempt due to:
Full ISO 50001 certification covering all in-scope energy consumption;
Total energy consumption below 40,000 kWh; or
Zero energy consumption
Completing energy audits for any significant energy consumption not covered by an alternative compliance route.
Preparing and maintaining an ESOS Report.
Sharing the ESOS assessment findings and supporting documentation with relevant group undertakings.
Obtaining Board-level sign-off confirming that the assessment findings have been reviewed.
Submitting a compliance notification through the MESOS online reporting system.
Maintaining an evidence pack containing the ESOS report, compliance notification, and supporting records.

In the third compliance period participants using ISO 50001 as an alternative route to compliance must now complete some additional requirements, which are outlined in the ISO 50001 FAQ above

Teamwork can support your organisation throughout the ESOS process, from qualification assessments through to compliance reporting, Action Plans and Annual Progress Updates.

Do we need external verification or assurance?

In most cases, yes. Organisations undertaking an ESOS assessment must appoint an approved ESOS Lead Assessor to oversee, review, or carry out the energy audits and confirm that the overall ESOS assessment meets the scheme requirements.

However, if your organisation is fully covered by a certified ISO 50001 Energy Management System that covers all energy consumption within the scope of ESOS, you do not need to appoint an ESOS Lead Assessor. The certification must be valid for the relevant compliance period and cover the assets and activities that make up your total energy consumption.

Regardless of the compliance route used, organisations must still:

Calculate Total Energy Consumption and, where applicable, Significant Energy Consumption
Calculate energy intensity ratios.
Prepare and maintain an ESOS Report
Share relevant ESOS findings with group undertakings.
Obtain Board-level approval confirming that:
- the assessment findings and recommendations have been reviewed;
- the organisation is ESOS compliant; and
- the information submitted within the compliance notification is accurate.
- Submit an ESOS compliance notification to the Environment Agency.
- Prepare an ESOS Action Plan and submit Annual Progress Updates.
- Maintain an evidence pack containing the required compliance records.

The exact requirements for the ESOS Report, compliance notification, and evidence pack will vary depending on the compliance route selected, such as ESOS energy audits or ISO 50001 certification.

Teamwork can guide you through every stage of ESOS compliance, helping you select the most suitable compliance route and ensuring all requirements are met. From qualification assessments and energy audits to ESOS Lead Assessor sign-off, compliance notifications, Action Plans, and Annual Progress Updates, we provide practical support to make compliance straightforward and cost-effective.