Public sector exemptions
Public sector organizations are generally exempt from ESOS requirements 1.
This includes central government departments, local authorities, NHS trusts, educational institutions, and other public bodies funded primarily through taxation.
However, publicly-owned commercial entities operating in competitive markets may still be subject to ESOS depending on their structure, funding sources, and commercial activities.
Mixed public-private arrangements require case-by-case assessment.
Low energy consumption exemptions
Organizations with total annual energy consumption below 40,000 kWh across all UK operations are exempt from lead assessor requirements and can use simplified compliance routes under the ESOS Regulations 2014 2, as amended by SI 2023/1182 3.
This threshold applies to total consumption including electricity, gas, transport fuels, and other energy sources.
Organizations near this threshold should monitor consumption carefully as breaching 40,000 kWh triggers full ESOS requirements.
Low Consumption Threshold
Annual energy consumption below which organizations are exempt from ESOS lead assessor requirements
ISO 50001 certification exemptions
Where a certified ISO 50001 energy management system covers total energy consumption, or significant energy consumption — the areas comprising at least 95% of the total — the participant is deemed to have complied with the duties to appoint a lead assessor, carry out an ESOS energy audit and produce an ESOS report 7 2. Certification does not have to reach 100% of energy use, and a notification of compliance is still required.
The ISO 50001:2018 standard provides the energy management system framework 4 accepted by the Environment Agency as a compliance route.
ISO 50001 provides equivalent energy assessment and efficiency identification through systematic energy management processes.
Where certification covers only part of consumption, the exemption applies only to the certified portion — the remainder must still be audited and a lead assessor appointed to reach the 95% threshold.
New exclusions under SI 2026/701
The Energy Savings Opportunity Scheme (Amendment) Regulations 2026 (SI 2026/701) came into force on 22 July 2026 and added two exclusions that matter for Phase 4 8.
Regulation 33A — zero energy consumption. An undertaking with zero energy consumption in the reference period need not carry out an ESOS assessment and need not appoint a lead assessor 7.
A notification of compliance is still required.
The insolvency exclusion is wider. Regulation 6 of SI 2026/701 amends regulation 16 of the 2014 Regulations so that undertakings in insolvency proceedings at any point between the qualification date and the compliance date are excluded 8.
Group undertakings of an insolvent large undertaking are excluded too — unless another large undertaking in the group is solvent.
Sub-threshold qualification rules
Organizations that fall below ESOS qualification thresholds (250+ employees, or £44m+ turnover AND £38m+ balance sheet, per the ESOS Regulations 2014 as amended 2) must fail to qualify for two consecutive accounting periods before losing their ESOS obligations 1.
This rule provides stability for compliance planning and prevents frequent changes in ESOS status for organizations operating near qualification boundaries.
Organizations should plan compliance activities assuming continued obligations until confirmed exemption.
Group exemption arrangements
ESOS operates group-wide qualification rules where single qualifying entity triggers obligations for entire UK group 2.
Conversely, if the qualifying entity becomes exempt, this can affect group-wide obligations, subject to the two-consecutive-period rule 1.
Group exemptions require careful coordination across corporate structures to ensure accurate qualification assessment and compliance planning.
Parent companies should monitor subsidiary qualification status for group-wide impact.
Alternative compliance routes
Even qualifying organizations have alternative compliance routes that may reduce audit requirements.
These include combined approaches mixing energy audits with ISO 50001 certification to achieve required 95% coverage.
Organizations should evaluate which compliance routes best suit their operations, existing energy management systems, and strategic objectives.
Early planning allows optimal route selection and resource allocation.
Compliance Routes
≥95% energy consumption coverage
Energy management system certification
Mixed audit and ISO 50001 coverage
Exemption verification and evidence
Organizations claiming ESOS exemptions must maintain evidence supporting exemption status including energy consumption records, public sector classification, ISO 50001 certificates, or qualification threshold calculations, per Environment Agency ESOS compliance guidance 5 3.
The Environment Agency 6 may request exemption verification as part of compliance monitoring.
Organizations should document exemption basis clearly and retain supporting evidence for inspection purposes in line with the Environment Agency’s Phase 4 guidance, published 30 July 2026 7.
Are public sector organizations exempt from ESOS?
Public sector organizations are generally exempt from ESOS requirements.
This includes central government departments, local authorities, NHS trusts, and other public bodies.
However, publicly-owned commercial entities operating in competitive markets may still be subject to ESOS depending on their structure and activities.
What is the 40,000 kWh exemption threshold?
Organisations with total annual energy consumption below 40,000 kWh across all UK operations do not need to appoint a lead assessor.
The threshold applies to total consumption including electricity, gas, transport fuels and other energy sources.
A notification of compliance is still required.
How does ISO 50001 certification provide ESOS exemption?
Where a certified ISO 50001 energy management system covers total energy consumption, or significant energy consumption — the areas comprising at least 95% of the total — the participant is deemed to have complied with the duties to appoint a lead assessor, carry out an ESOS energy audit and produce an ESOS report.
Certification does not have to reach 100%.
Where coverage is partial, the exemption applies only to the certified consumption; the rest must still be audited with a lead assessor appointed.
A notification of compliance is required either way.
What happens if an undertaking has zero energy consumption?
New regulation 33A, inserted by SI 2026/701, provides that an undertaking with zero energy consumption in the reference period need not carry out an ESOS assessment and need not appoint a lead assessor.
A notification of compliance is still required.
Does insolvency remove an ESOS obligation?
SI 2026/701 widened the insolvency exclusion.
Undertakings in insolvency proceedings at any point between the qualification date and the compliance date are excluded, as are group undertakings of an insolvent large undertaking — unless another large undertaking in the group is solvent.
What are the sub-threshold qualification rules?
Organizations that fall below ESOS qualification thresholds (250+ employees, or £44m+ turnover AND £38m+ balance sheet) must fail to qualify for two consecutive accounting periods before losing their ESOS obligations.
This provides stability for compliance planning around threshold boundaries.
How do group exemptions work under ESOS?
If any single UK entity within a corporate group meets ESOS qualification criteria, the entire UK group becomes subject to ESOS.
Conversely, if the qualifying entity becomes exempt, this can affect group-wide obligations, though the two-consecutive-period rule still applies to prevent frequent status changes.
Related guides & references
ESOS: the UK’s energy assessment scheme
Complete overview including qualification criteria and group aggregation rules
ESOS Phase 4 compliance guide
Phase 4 qualification criteria and exemption thresholds in detail
ESOS lead assessor requirements
When lead assessors are required and exemption circumstances
ESOS Requirements: The 7 Compliance Steps
Full compliance process including alternative routes and exemptions
ISO 50001 vs ESOS — which compliance route
The certification route that removes the lead-assessor review for covered energy use
ESOS legislation — SI 2014/1643 and SI 2023/1182
Where the exemption categories come from in the regulations
Authority Sources
- Energy Savings Opportunity Scheme (ESOS) — Overview
- Energy Savings Opportunity Scheme Regulations 2014
- ESOS (Amendment) Regulations 2023
- ISO 50001:2018 — Energy Management Systems
- ESOS Phase 3 and Phase 4 Guidance for Participants
- Comply with the Energy Savings Opportunity Scheme (ESOS) phase 4
- ESOS (Amendment) Regulations 2026
- Environment Agency — ESOS enforcer
Last verified: 1 August 2026 — Facts cross-checked against SI 2026/701 and the Environment Agency’s ESOS phase 4 guidance (30 July 2026)