UK ETS: Guidance for ultra small emitters
Information for ultra small emitters (USEs) on eligibility and compliance.
Installations that emit less than 2,500 tonnes of carbon dioxide equivalent (CO2eq) had the opportunity to apply under the baseline data collection window (from April - June 2025) for Ultra-Small Emitter (USE) status for the 2026 – 2030 allocation period.
USE installations must continue to monitor their emissions and notify their regulator if their emissions exceed the agreed threshold.
Aircraft operators cannot apply to register as ultra-small emitters. Read guidance for aircraft operators with low emissions.
Lists of qualifying USEs by allocation period
Qualifying USEs for the 2026 - 2030 allocation period
An installation will only be a USE in the 2026 to 2030 allocation period if it is included in the ultra-small emitter list for 2026 to 2030.
Qualifying USEs for the 2021 - 2025 allocation period
An installation was only considered to be USE in the 2021 to 2025 allocation period if it was included in the ultra-small emitter list for 2021 to 2025.
Eligibility for the 2026 to 2030 allocation period
Eligible installations needed to meet one of the following conditions:
- if a regulated activity was carried out at an installation on or before 1 January 2021, that installation’s reportable emissions were 2,499 tonnes of CO2eq or below in scheme years 2021, 2022 and 2023
- if a regulated activity commenced at an installation between 2 January 2021 and 1 January 2022, that installation’s reportable emissions were 2,499 tonnes of CO2eq or below in scheme years 2022, 2023 and 2024
- if a regulated activity commenced at an installation between 2 January 2022 and 1 January 2023, that installation’s reportable emissions were 2,499 tonnes of CO2eq or below in scheme years 2023 and 2024
- if a regulated activity commenced at an installation between 2 January 2023 and 1 January 2024, that installation’s reportable emissions were 2,499 tonnes of CO2eq or below in scheme year 2024
Emissions monitoring requirements for a USE
An installation must monitor its emissions and notify its regulator if it emit more than 2,500 tonnes of CO2eq in any scheme year.
An installation must monitor its emissions by following the methodology set out in its monitoring plan. The plan must be kept up to date in line with the relevant provisions in the UK ETS Order and must remain fit for purpose.
When an installation no longer qualifies as a USE
An installation cannot voluntarily cease to be a USE during an allocation period.
An installation will no longer qualify as a USE if its reportable emissions exceed 2,500t CO2eq in:
- any of the 2021 to 2023 scheme years in relation to the 2021 to 2025 allocation period
- any of the 2026 to 2028 scheme years in relation to the 2026 to 2030 allocation period
If an installation ceases to be a USE, it must notify its regulator by 31 March of that scheme year. If it does not, it will be liable to a civil penalty.
The regulator will then send a notice requiring the installation to either:
- return to the UK ETS main scheme as a full participant
- apply for Hospital and Small Emitter (HSE) scheme (if the installation meets the eligibility criteria)
The installation must then apply for either a greenhouse gas emissions permit or a HSE permit.
An installation will remain liable for any unpaid penalties and any further sanctions applied for non-payment of those penalties arising from its time as a USE.
See also:
- Participating in the UK ETS for an overview of the scheme and first steps for new participants
- Technical guidance and other tools for current scheme participants
- Operation of the UK ETS markets for how to take part in auctions and trade on the secondary market
- Policy aims of the UK ETS for an overview of existing policy and next steps for developing the scheme
- UK ETS reports and reviews for scheme or compliance data and other reporting by the Authority
Updates to this page
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Added USE list 2026 to 2030.
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USE Verification report template updated and improved. Where possible verifiers should use the updated version, but the earlier version will be accepted.
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Eligibility criteria for the 2026 to 2030 allocation period updated.
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Updated the Environment Agency (EA) contact email.
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Added templates and guidance on how existing USEs should apply for USE status for the 2026 to 2030 allocation period.
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The application dates for the 2026 to 2030 allocation period will now be from 1 April to 30 June 2025.
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First published.