Energy Savings Opportunity Scheme (ESOS)

Energy Savings Opportunity Scheme (ESOS): mandatory four-yearly energy audits covering at least 95% of total energy use, with a director-approved action plan and annual progress updates.

Jurisdiction
uk
Status
active
Category
First deadline
Phase 4 qualification date 31 December 2026; compliance deadline 5 December 2027, with an action plan due afterward.
Who must comply
Applies to UK undertakings and corporate groups that either employ 250 or more people, or have annual turnover above GBP 44 million together with a balance sheet total above GBP 38 million. It covers organizations across all sectors. Energy assessments must cover at least 95% of total energy consumption.
Penalties
Civil penalties enforced by the Environment Agency: up to GBP 5,000 plus GBP 500 per day (max 80 days) for late or missing notification; up to GBP 50,000 plus GBP 500 per day for failing to complete an assessment; up to GBP 5,000 for inadequate records or obstruction; plus public naming of the breach. Cumulative fines can reach around GBP 90,000 per phase.

What it is

The Energy Savings Opportunity Scheme (ESOS) is a mandatory UK energy assessment scheme established under the Energy Savings Opportunity Scheme Regulations 2014 and administered by the Environment Agency. It requires large organizations to measure their Total Energy Consumption (TEC), identify areas of significant energy use, and either conduct energy audits or implement ISO 50001 certification. The scheme runs in four-year cycles and supports the UK's broader net-zero goals by identifying energy-saving opportunities and enforcing regular energy performance reviews. Amendments made in 2023 added action plans, progress updates, and enhanced audit coverage.

Who must comply

ESOS applies to UK undertakings and corporate groups that meet either qualification threshold: 250 or more employees, or annual turnover exceeding GBP 44 million together with a balance sheet total exceeding GBP 38 million. It covers organizations across all sectors, from agriculture to telecommunications, and qualifying entities must repeat the assessment in each four-year phase.

What you must disclose

Qualifying organizations must determine Total Energy Consumption (TEC) over a continuous 12-month period, identify significant energy consumption covering at least 95% of TEC, and complete energy audits or hold ISO 50001 certification. They must produce energy-intensity ratios (buildings, transport, and process), an energy-saving opportunities register (with cost, savings, and ROI), a director-approved Action Plan, and annual progress updates, and submit a signed compliance notification. A certified ESOS Lead Assessor from a government-approved list must review and sign off the assessment unless the organization's TEC is below 40,000 kWh.

Timeline

ESOS operates in four-year compliance cycles under the Energy Savings Opportunity Scheme Regulations 2014. Phase 1 was introduced in July 2014 and concluded on 5 December 2015. Phase 3 used a qualification date of 31 December 2022 with a compliance deadline of 5 June 2024 and an Action Plan due by 5 December 2024, requiring coverage of at least 95% of total energy consumption.

Phase 4 uses a qualification date of 31 December 2026 with a compliance deadline of 5 December 2027, and Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) are no longer valid routes. Amendments made in 2023 expanded obligations to add Action Plans, annual progress updates, and enhanced audit coverage under a new statutory instrument.

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