Is Your Business Prepared for ESOS Phase 4?
ESOS Phase 3 ended on 6 August 2024, and the requirements for Phase 4 are even stricter than the previous phase. Businesses need to report the energy savings achieved against action-plan commitments and provide reasons for measures that were not implemented or targets that have not been met.Â
It’s essential to get ahead of the curve – get your ESOS compliance sorted early and identify ‘quick wins’ for energy savings.Â
To prepare for ESOS Phase 4, businesses must review qualification criteria by 31 December 2026 and submit final compliance through the Gov.uk ESOS portal by 5 December 2027. A full year of energy data needs to be collected before the end of 2027, with comprehensive energy audits conducted for at least 95% of total consumption to identify cost-effective energy-saving measures. ISO 50001 certification can also be used to satisfy ESOS requirements.Â
Working with Consultiv Utilities means you can look to meet obligations early, avoid last-minute stress, and unlock real energy savings through strategic audit insights. Book your free ESOS consultation to understand if your business needs to meet Phase 4 requirements and how our team can help you get this sorted ahead of the 2027 deadline.Â
Book your free ESOS Phase 4 consultation today.
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What’s Included in Our ESOS Compliance Service?
1. Qualification Assessment
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During your initial qualification assessment, we will assess whether your business meets the employee or financial thresholds for the ESOS scheme.
2. Energy Consumption Measurement
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We measure energy usage across buildings, industrial processes, transport and other energy uses for a full 12-months, which we will then use for your energy audit.
3. ESOS Energy Audit
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Where required, our team will conduct a comprehensive energy audit covering at least 95% of your total energy consumption.
4. ESOS Evidence Pack
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We will assemble your ESOS evidence pack, which will be reviewed and signed off by an experienced ESOS lead assessor
5. Environment Agency Submission
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We can complete and submit your ESOS notification on MESOS, ensuring all supporting documentation is correct the first time around.
6. Action Plan
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Our ESOS specialists will draft your action plan and report on the progress made on your Phase 3 commitments and targets, which is now mandatory in ESOS Phase 4.
Which Businesses Must Comply with ESOS Phase 4?
UK businesses that qualify as a ‘large undertaking’ on the qualification date of December 31, 2026 must comply with ESOS Phase 4 requirements. To be qualified as a ‘large undertaking’, the business must meet either of the following conditions:
- Employ 250 or more people
- Have an annual turnover exceeding £44 million and an annual balance sheet exceeding £38 million
If a corporate group in the UK contains at least one ‘large undertaking’ that meets the above criteria, the entire group must comply with the ESOS scheme. Charities or not-for-profit organisations are also required to comply if they meet the criteria, but some public-sector bodies are exempt from ESOS.
At Consultiv Utilities, we provide end-to-end compliance support for large UK organisations to help them meet ESOS Phase 4 requirements and future phases.
Unsure if your business needs to comply with ESOS Phase 4?
Book your free qualification check to find out if you meet the latest qualification criteria.Â
Why Choose Consultiv Utilities for ESOS Compliance?
Working with a trusted energy consultancy ensures that your ESOS submission is accurate, efficient, and fully compliant. At Consultiv Utilities, we provide:Â
- Experienced ESOS lead assessors and energy consultants
- End-to-end management of audit, analysis, and submission
- A proven record of helping multi-site organisations achieve compliance ahead of deadlines
- Ongoing guidance through Phase 4 and beyond, with transparent reporting and measurable outcomes
Don’t delay – get your ESOS Phase 4 compliance sorted today with help from the Consultiv Utilities team.Â
Why Choose Consultiv Utilities?
ESOS Phase 4: Key Information
Deadlines:
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Qualification date -
31 December 2026
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Submission date
5 December 2027
Qualification Criteria:
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If your organisation qualifies as a ‘large undertaking’, you must comply with ESOS Phase 4.
This means you:
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Employ 250 or more people
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Have an annual turnover exceeding £44 million and an annual balance sheet total exceeding £38 million
Major Changes From Phase 4:
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Removal of alternative compliance routes
e.g. Display Energy Certificates (DECs) and Green Deal Assessments (GDAs)
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Must now report energy savings achieved and review action-plan commitments,
e.g. an explanation for any measures that were not implemented
ESOS Compliance Timeline
While the December 2027 deadline might seem far away, a realistic ESOS compliance process can take 6-12 months from start to finish. For multi-site organisations, it may take even longer.Â
ESOS compliance involves:
- Appointing a Lead Assessor and scoping the audit – 4 to 8 weeks
- Gathering 12 months of reference period energy data across all sites – 6 to 12 weeks, often longer for complex multi-site organisations
- Conducting detailed site audits covering at least 95% of consumption – variable, but typically 8 to 16 weeks for larger organisations
- Preparing the assessment report and opportunity register – 4 to 6 weeks
- Board review and sign-off – 2 to 4 weeks
- Submission to the Environment Agency – 1 to 2 weeks
The window for completing ESOS compliance in a comfortable window is already narrowing – it’s important not to let your business get left behind and risk not being ready for the December 2027 deadline.Â
Waiting until 2027 means this is a real risk, especially as demand for Lead Assessors increases and other organisations scramble to get their compliance sorted in time. Get started today with Consultiv Utilities with a free consultation and find out how long the process is likely to take for your business.Â
What Is the Difference Between ESOS Phase 3 and Phase 4?
ESOS Phase 4 introduces more accountability, holding organisations to the commitments made in their Phase 3 action plan. Businesses must now report on the progress made against their Phase 3 commitments and provide formal explanations for unmet targets.Â
Key Differences in ESOS Phase 4:
- Accountability for the Phase 3 action plan, commitments and targets, including an explanation for any unmet targets
- Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as additional compliance routes
- Organisations must rely on energy audits signed off by a lead assessor or ISO 50001 accreditation for full compliance
What is Unchanged From Phase 3 to Phase 4:
- Qualification criteria for what constitutes a ‘large undertaking’
- Core requirements are the same, including the need to audit at least 95% of total energy consumption
Want to know more about ESOS Phase 4? We’ve got more detailed information in our blog, ‘ESOS Phase 4: Everything you need to know’.Â
Achieve ESOS Compliance Through ISO 50001
If your organisation holds ISO 50001 certification covering all sites, you may already meet ESOS obligations. A valid, UKAS-accredited ISO 50001 Energy Management System (EnMS) is an approved alternative compliance route for the ESOS Scheme. As part of our ESOS Compliance service, our team verifies certification coverage and advises on any additional audits needed to ensure total compliance.
Not sure if your business has already met ESOS requirements? Book a free consultation with our team to find out if there’s anything more your business needs to do to be ready for the 2027 deadline.Â
Speak to Our ESOS Compliance Team and Get Prepared For ESOS Phase 4
ESOS should not be seen as a tick-box exercise. We turn compliance data into actionable insights that reduce ongoing energy costs and improve operational efficiency.
Our consultancy helps you develop long-term energy management plans that align with corporate sustainability and carbon-reduction targets.
Start Your ESOS Compliance Journey Today with Consultiv Utilities
Book an initial consultation with Consultiv Utilities to begin your ESOS audit and ensure timely compliance for Phase 4 ahead of the 2027 deadline.Â
We’ll outline your qualification status, map the audit process, and provide a tailored plan to meet all Environment Agency requirements efficiently and cost-effectively.
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Our Compliance Services
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Climate Change Levy Relief
British Industrial Competitiveness Scheme (BICS) Compliance
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FAQs
What does an ESOS audit involve for large organisations?
Organisations must identify all energy use across:
- Buildings
- Transport
- Industrial processes
- Use 12 consecutive months of data that includes the qualification date
- Express consumption in kWh or other common energy units
- Identify energy use and efficiency for significant areas
Once the audit is complete, organisations must prepare an ESOS evidence pack documenting data sources, methodologies, findings and recommendations, assessor details and board-level sign off.Â
This process can often be complicated and require a dedicated expert to help ensure all compliance is thoroughly investigated – that’s where we can help! Contact us today to find out more about the assistance we can offer you throughout your ESOS audit process.
How can ISO 50001 certification help with ESOS compliance?
ISO 50001 is the international standard for energy management systems (EnMS). ISO 50001 certification can fully or partly satisfy ESOS compliance requirements, depending on its scope. Â
What are the penalties for missing the ESOS compliance deadline?
Missing ESOS deadlines can lead to EA fines up to £50,000, plus £500 per day for ongoing breaches. Penalties cover missed audits, failing to notify, poor records, ignoring notices, and giving false information, which can also be publicly disclosed.
When should businesses start preparing for ESOS Phase 4?
We would recommend starting compliance as soon as you can in 2026. By being proactive, you can ensure you have an ESOS lead assessor scheduled to support you in plenty of time to comply. Acting swiftly will also help you identify energy savings so you can implement energy efficiencies more quickly.Â
What information is required for an ESOS submission to the Environment Agency?
An ESOS submission to the Environment Agency requires detailed energy data across your organisation, including energy audits, consumption records, and compliance evidence. Gathering this information can be complex and time-consuming, but we can help streamline the process and ensure an accurate submission.
How can Consultiv Utilities support ongoing ESOS compliance after submission?
Consultiv Utilities supports ongoing ESOS compliance by tracking energy use, updating records, scheduling audits, and ensuring timely notifications. We also help implement ESOS recommendations, turning insights into actions that can improve efficiency, deliver savings and maintain ongoing compliance.
