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Guidance

UK Emissions Trading Scheme for maritime: how to comply

Guidance to help maritime operators understand and meet their compliance obligations under the UK Emissions Trading Scheme (UK ETS).

From:
Environment Agency
Published
22 June 2026

About this guidance

This guidance will help maritime operators regulated by the Environment Agency understand and comply with their obligations under the UK ETS. These obligations are set out in The Greenhouse Gas Emissions Trading Scheme Order 2020 No.1265 (the Order).

You will need to comply with the UK ETS as soon as you become a maritime operator.

If you are not sure about your UK ETS obligations, or any aspect of this guidance, contact your regulator.

Regulators and their contact details

There are 4 regulators for maritime operators regulated under the UK ETS.

If you are a maritime operator, you can work out who your regulator is by the location of your registered office or place of residence. For:

When you contact your regulator, you will need to provide the following information:

  • first name and surname for your Manage your UK Emissions Trading Scheme reporting service (METS) primary contact
  • email address for your METS primary contact 
  • International Maritime Organization (IMO) unique company and registered owner identification number of the maritime operator
  • legal entity name of the maritime operator

The Environment Agency also serves as the registry administrator of the UK ETS Registry for the UK on behalf of all regulators. Contact the registry administrator at etregistryhelp@environment-agency.gov.uk.

Understand whether the UK ETS applies to you

The UK ETS applies to you if you are a maritime operator.

Under the UK ETS, you are a maritime operator of a ship if you are performing maritime activities in that ship and one of the following applies. You are either the registered owner of the ship or the International Safety Management (ISM) company that has taken on responsibility from the registered owner for:

  • the operation of the ship
  • compliance with the ISM Code
  • compliance with UK ETS obligations (under the terms of a legally binding written agreement)

You will only be a maritime operator with monitoring, reporting and surrender obligations in a scheme year in which you meet all the relevant criteria. If you do not meet the relevant criteria, you will be exempt for that scheme year.

The registered owner of a ship is the person named as its owner on the certificate of registry. This is the certificate issued by the authority responsible for the registration of ships in its State of registration. 

If you are not the registered owner of a ship listed in your emissions monitoring plan, you will need to complete a declaration in METS concerning the delegation to you of the UK ETS responsibilities in respect of that ship.

If the regulator has not identified the person responsible for a maritime activity in a ship , they will treat the registered owner of the ship as the maritime operator responsible for compliance with UK ETS obligations in relation to that maritime activity.

Maritime operators have legal obligations under UK ETS. If you do not comply with these obligations, you may be subject to civil penalties.

If you think you may be a maritime operator with obligations under the UK ETS, or if you are not sure whether you are a maritime operator, contact your regulator.

The following examples are scenarios where maritime operators meet and do not meet the maritime operator criteria. 

Example 1: maritime operator criteria met

Motor vessel (MV) Example Ship is a cargo vessel. In the 2027 scheme year, the following arrangements are in place.

January to March 2027: The registered owner, Alice Shipping Ltd, operates the vessel directly. No other company has taken on ISM responsibilities.

April to December 2027: Alice Shipping Ltd has passed on the operation of the ship and compliance with the ISM Code in respect of it to Bob Shipping Ltd. Alice Shipping Ltd has also delegated responsibility for the compliance with the UK ETS for the ship to Bob Shipping Ltd in a in a legally binding written agreement. Under this agreement, Bob Shipping Ltd becomes responsible for:

  • the operation of the ship
  • compliance with the ISM Code
  • all UK ETS obligations for the vessel

Outcome:

  • January to March: Alice Shipping Ltd is the maritime operator because it is the registered owner and has not transferred ISM and UK ETS compliance requirements
  • April to December: Bob Shipping Ltd is the maritime operator because it meets all 3 elements of the criteria

Each company only has UK ETS monitoring, reporting and surrender obligations for the part of the scheme year in which it meets the criteria.

Example 2: ISM company does not meet the criteria to be the maritime operator

MV Example Ship 2 is a passenger vessel. In the 2028 scheme year, the following arrangements apply:

  • the registered owner is Alice Shipping Ltd
  • Alice Shipping Ltd enters into an agreement with Bob Shipping Ltd, under which Bob Shipping Ltd operates the ship and is responsible for compliance with the ISM Code in respect of it

However, Alice Shipping Ltd does not delegate responsibility for complying with UK ETS requirements to Bob Shipping Ltd under a legally binding written agreement.

Bob Shipping Ltd does not become the maritime operator because it does not meet all 3 elements of the criteria. Therefore, Alice Shipping Ltd is the maritime operator with responsibility for complying with UK ETS requirements for the entire 2028 scheme year.

What a maritime activity is

A maritime activity under the UK ETS includes the following activities performed by ships of 5,000 gross tonnage (GT) or more, other than an excluded activity:

  • a voyage between one UK port of call and the same or another UK port of call
  • an in-port activity in a UK port of call

Excluded activities are not regulated under UK ETS.

What a port of call is

A port, for the purposes of the UK ETS, includes both:

A port of call is any port a ship arrives at or is present at where either:

  • passengers and crew embark or disembark
  • cargo is loaded onto or unloaded

Stops for the exclusive purpose of the following are not a port of call:

  • refuelling
  • getting supplies in connection with the operation of the ship
  • relieving the crew of a ship other than an offshore ship
  • going into dry dock
  • getting repairs to the ship or its equipment
  • sheltering from adverse weather conditions
  • getting assistance where the ship is in distress

The arrival or presence of a ship in a port made necessary by the following purposes is also not a port of call: 

  • a medical emergency
  • search and rescue activities
  • providing assistance to a ship in distress

For example, where a ship on a voyage between 2 UK ports of call stops at a non-UK port to obtain repairs, the voyage will be within the scope of UK ETS. 

What a voyage is

Under UK ETS, a voyage:

  • is any movement of a ship from its last berth or ship-to-ship transfer within one UK port of call to its first berth or ship to-ship transfer in the next UK port of call or on its return to the same UK port of call
  • does not have any intervening stop at a port of call outside the UK

The following are considered part of a voyage:

  • time spent moored or at anchor, including at an outer anchorage
  • time spent at an offshore structure that is not an in-port activity

Your voyage is not regulated under the UK ETS if it involves the movement of a ship from a UK port of call to a port of call outside the UK.

What an in-port activity is

Under the UK ETS, in-port activities are time spent at berth and movements in port as part of a UK port of call .

You must account for all emissions from in-port activities in a UK port of call even if your ship is not performing a voyage between UK ports of call.

A ship is at berth in a port when it:

  • is securely moored or anchored while loading or unloading cargo or hotelling
  • spends any time not engaged in cargo operations

Movements in port are any movement of a ship within a port of call that are not part of the voyage. For example, the movement of a ship from one berth to another.

What the excluded activities are

The excluded activities under the UK ETS are as follows.

Those performed exclusively for:

  • military purposes
  • search and rescue purposes
  • firefighting

  • providing humanitarian aid or assistance

  • carrying out any other government function

  • the transport, on official mission of a reigning Monarch and their immediate family, or a head of State of a State other than the UK

  • the transport, on official mission of Ministers of a national government of a country other than the UK

Those carried out in one of the following ships:

  • a ship in the armed services of the UK or another country (including naval auxiliary ships)
  • a wooden ship of primitive build
  • a ship propelled exclusively by non-mechanical means
  • a ship that operates a Scottish ferry service
  • a ship of less than 5000 GT
  • up to and including 31 December 2026, an offshore ship

 Those carried out in a ship the principal use of which is: 

  • law enforcement (for example for border enforcement purposes or for customs purposes)
  • assisting marine navigation or safe passage
  • government surveillance and protection of the marine environment
  • fish-catching and fish processing
  • carrying out or facilitating publicly funded research
  • undertaking coastguard or search and rescue activities
  • responding to medical emergencies

Where a ship undertakes excluded activities, any ancillary voyages (for example, for positioning) and any related in-port activities are also excluded from the UK ETS scope.

The following examples are scenarios to show which activities are within the scope of the UK ETS.

Example 1: A voyage between UK ports of call

MV Example Ship, 12,000 GT, departs Liverpool after loading cargo at berth. It sails directly to Bristol, where it berths and unloads.

This is a maritime activity because:

  • the ship moves from its last berth in one UK port of call (Liverpool)
  • the ship moved to its first berth in another UK port of call (Bristol)
  • there are no intervening port calls outside the UK

This movement is a voyage under the UK ETS. All emissions during the voyage must be monitored and reported.

Example 2: International voyage with in‑port activities

MV Example Ship 2, 7,500 GT, arrives at Southampton from Singapore (a non‑UK port).

It spends:

  • 18 hours at berth unloading containers
  • 2 hours moving from one berth to another within the port
  • 6 hours hotelling while awaiting departure

This is a maritime activity because even though the ship did not perform a UK‑to‑UK voyage, its in‑port activities in a UK port of call are within scope.

All emissions from time spent at berth and hotelling, and from movements within the port of call, must be reported under UK ETS.

Example 3: UK ETS voyage including a stop that is not a port of call

MV Example Ship 3 loads cargo in Hull and stops at Plymouth only to:

  • take on fuel
  • replace 2 crew members

It does not load or unload cargo or embark or disembark passengers or crew.

It then carries on to Bristol to unload cargo.

The stop in Plymouth is not a UK port of call because it is a stop exclusively for refuelling and relieving crew. The related maritime emissions are:

  • all the emissions during the voyage from Hull to Bristol
  • the in-port emissions in Hull and Bristol
  • any emissions released during the stop in Plymouth, as this was not a port of call and stopping there did not end the voyage

Delegation of UK ETS responsibility 

The registered owner of a ship can delegate the obligations to comply with the UK ETS to the ISM company under a legally binding written agreement.

The delegation can only take effect on or after the date that the legally binding written agreement is completed. It is not possible to backdate the delegation of UK ETS responsibility. 

If the agreement sets out a future commencement date for the delegation, you should notify the Environment Agency of this.

If you are not the registered owner of one or more ships that you are including in your emissions monitoring plan, you must:

  • provide contact details of each registered owner that has delegated its UK ETS responsibilities to you
  • complete the relevant declaration of delegated responsibility in METS

The declaration of delegated responsibility that you must complete in METS states that you:

a) are the ISM Company which has assumed the responsibility for the operation of the ship from its registered owner and who, on assuming such responsibility, has agreed to take over all duties and responsibilities imposed by the ISM Code

b) have entered into a legally binding written agreement with the registered owner of the ship to comply with the obligations of the maritime operator under the Order in respect of the ship

c) will notify the regulator in writing of any change to the agreement referred to in paragraph (b) that affects your responsibility for compliance with the obligations under the Order in respect of the ship within 14 days of the change

d) accept full legal liability under the Order arising from any failure to comply with the obligations of the maritime operator under the Order in respect of the ship

e) will provide to the regulator on request a copy of the agreement referred to in paragraph (b) together with any related documents required to satisfy the regulator of the existence and nature of the agreement

You must inform the Environment Agency within 14 days if the legally binding written agreement delegating responsibility is terminated or changed in a way that materially affects the delegation. You must do this by varying the relevant section of your emissions monitoring plan in METS.

If you enter into a legally binding written agreement delegating responsibility to you for a ship that is not already included in your emissions monitoring plan, this is a significant change, and you must:

  • apply to vary your emissions monitoring plan to add that ship
  • complete a related declaration of delegated responsibility

Complying with your UK ETS requirements

To comply with your requirements under the UK ETS, you must do the following:

  1. Set up your maritime operator account in METS.

  2. Apply to your regulator for an emissions monitoring plan within 42 days of starting your first UK ETS maritime activity.

  3. Monitor your greenhouse gas emissions from maritime activities for each scheme year.

  4. Verify and report your maritime emissions by 31 March in the year following the scheme year.

  5. Calculate any applicable surrender deduction for inclusion in your annual emissions report.

  6. Surrender from your maritime operator holding account by the applicable statutory surrender deadline the number of allowances equal to your emissions figure for surrender, which is your maritime emissions figure minus any surrender deduction.

The first scheme year for maritime operators runs from 1 July 2026 to 31 December 2026. 

From 1 January 2027, the scheme year runs from 1 January to 31 December in each calendar year.

You will need to acquire allowances to meet your surrender obligation. For each tonne of carbon dioxide (CO2) equivalent in your emissions figure for surrender, you must surrender one allowance. Your authorised representative can surrender allowances at any time from your maritime operator holding account in the UK ETS Registry.

The greenhouse gas emissions you need to monitor are your emissions of CO2, nitrous oxide (N2O) and methane (CH4) arising from any maritime activity within the scope of the UK ETS. 

The surrender deadlines are:

  • 23:59 Greenwich Mean Time (GMT) on 30 April 2028 for the 2026 and 2027 scheme years 
  • 23:59 GMT on 30 April in the year following the scheme year from the 2028 scheme year onwards 

Your METS online account

Your regulator sends you messages and manages your applications, variations and report submissions through METS.

To set up your maritime operator account in METS, you will need to contact etmaritimehelp@environment-agency.gov.uk and provide the following details:

  • IMO unique company and registered owner identification number
  • operator name
  • contact name and email address

The Environment Agency will use this information to create your account.

You will receive an email confirming that your account has been created. You will need to accept your METS account by clicking on the verification link within 72 hours. If your link expires, contact etmaritimehelp@environment-agency.gov.uk.

If this is your first time logging into METS, you will also receive an email to sign into your METS account with two factor authentication to gain access.

Once the Environment Agency has activated your account, you can log in by following the instructions emailed to you.

In METS, you will be able to:

  • apply for and view your emissions monitoring plan
  • make payments for emissions monitoring plan applications
  • view guidance on how to use METS
  • apply to vary your emissions monitoring plan
  • set up permissions for your account users and add and remove users
  • link a verifier and a data provider to your account
  • send notifications to your regulator (and receive them from your regulator)
  • receive reminders of tasks you must or may need to take
  • view and amend certain reports and workflows
  • submit your annual emissions report
  • submit your improvement report (if needed)

The forms in METS are designed to help maritime operators provide the information needed. They include guidance on how to complete specific fields within the forms. The forms may also provide references to additional guidance or legislation where relevant.

Apply for an emissions monitoring plan

If you are a maritime operator that has performed a maritime activity, you must apply for an emissions monitoring plan at operator level within 42 days of starting that activity.

The emissions monitoring plan sets out how you must monitor and report your greenhouse gas emissions from maritime activities in line with the requirements of the Order. You must comply with the conditions of your emissions monitoring plan.

You must apply for an emissions monitoring plan in METS.

You can access your account in METS ETS Gateway using the login details provided by your regulator.

Once you gain access to METS, you’ll see a task to apply for an emissions monitoring plan in your work queue.

You must:

  • use the online form to complete and submit your emissions monitoring plan
  • list all the ships you have responsibility for in your emissions monitoring plan by submitting an upload of your fleet

You’ll be responsible for the emissions from maritime activities in any ship that you have UK ETS responsibility for, regardless of whether it is listed in your emissions monitoring plan.

You can complete the ‘ships and emissions factors’ section in METS: 

  • manually – complete the emissions monitoring plan by providing all the necessary information
  • by XML upload – upload the ships and emissions factor information through an XML file which meets the XSD schema requirements (download the schema from METS). Your data supplier may offer a UK ETS XML file you can use
  • by an application programming interface (API) – if your data monitoring plan data is already digitised, your data supplier may offer to transfer it to METS through an API

See the guidance section in METS for guidance on how to link your account to a data provider.

What your emissions monitoring plan must include

Your emissions monitoring plan must include:

  • emissions monitoring plan holder details (including legal entity details)
  • details of your activities, including geographical scope and purpose of activity (passengers, cargo and so on)
  • a list of ships you are responsible for under UK ETS
  • declaration in relation to any delegated responsibility for UK ETS
  • fuels, emissions sources, emissions factors and monitoring methods for each ship
  • details of procedures and systems related to monitoring and reporting, including in relation to any emissions reduction claims

You can access your emissions monitoring plan, including all the relevant details, on METS.

Which monitoring methods you will use

You must provide details of the monitoring methods you intend to use to work out the greenhouse gas emissions for each ship in your emissions monitoring plan. You must ensure that your chosen monitoring method is consistently applied. The monitoring methods are set out in full in Part 4 of the Order.

Methods A, B and C are calculation-based approaches. They apply to the time between 2 ports of call or time within a port of call

For each of these methods, you must work out whether the approach applied is the default or ship-specific. If ship-specific, you must record the associated uncertainty value.

You must also regularly perform suitable control activities, including:

  • cross-checking between the bunkering quantity as provided by the bunker delivery note and the bunkering quantity indicated by on-board measurement
  • taking corrective action if notable deviations are observed

Method D is a measurement approach. For this method, direct measurements of greenhouse gas emissions are used. You must record the associated uncertainty value.

Method A – Bunker delivery note and periodic stocktakes of fuel tanks

This method is based on the quantity and type of fuel as indicated on the bunker delivery note combined with periodic stocktakes of fuel tanks based on tank readings.

The fuel consumed over the period is made of both:

  • the fuel at the beginning of the period, plus deliveries, minus fuel available at the end of the period
  • the de-bunkered fuel between the beginning and end of the period

Method B – Bunker fuel tank monitoring on-board

This method is based on fuel tank readings carried out by appropriate methods such as automated systems, soundings and dip tapes for all fuel tanks on board. The tank readings should occur daily when the ship is at sea and each time the ship is bunkering or de-bunkering.

The cumulative variations of the fuel tank level between 2 readings is the fuel consumed over the period.

Method C – Flow meters for applicable combustion processes

This method is based on measured fuel flows on board.

Combine the data from all flow meters linked to relevant greenhouse gas emission sources to work out all fuel consumption for a specific period.

Method D – Direct CO2 emissions measurement

The direct greenhouse gas emissions measurement can be used for voyages and in port activities. If applied to all emission sources, fuel consumption is calculated using the measured emissions and the applicable emission factors.

This method is based on the determination of greenhouse gas emissions flows in exhaust gas stacks (funnels) by multiplying the greenhouse gas concentrations of the exhaust gas with the exhaust gas flow. 

What happens next

The Environment Agency will determine your application for an emissions monitoring plan within 2 months of the date it was duly made unless they agree a longer period with you.

An application is not ‘duly made’ until you have:

  • submitted the application form
  • provided all the information required
  • paid any fee required

Contact the Environment Agency as soon as possible if you have not applied for your emissions monitoring plan within the 42-day deadline.

Simplified monitoring for voyages

Simplified monitoring allows a maritime operator to record annual fuel consumption data for the ship instead of monitoring fuel use for each individual voyage.

When you can use simplified monitoring

You can only use a simplified approach to emissions monitoring in relation to a ship if all the following conditions are met within the same scheme year:

  • the ship is scheduled to complete more than 300 voyages
  • you are the intended maritime operator in respect of these scheduled voyages
  • the ship only undertakes voyages and in-port activities

Monitoring requirements under the simplified approach

If you are a maritime operator using simplified monitoring, you must record the:

  • total number of voyages in the scheme year
  • total annual fuel consumption by fuel type
  • emission factor for each fuel type
  • total annual greenhouse gas emissions by gas type

Example of using simplified monitoring

A shortsea ferry is scheduled to complete 420 voyages in a scheme year, all of which meet the definition of a “voyage” under the Order. The ferry is not scheduled to undertake movements that are not a voyage or an in-port activity.

Because it exceeds 300 voyages and performs no movements that are not a voyage or an in-port activity, the maritime operator may use simplified monitoring. No monitoring per-voyage is required. For the scheme year, the maritime operator reports:

  • 420 voyages
  • 3,200 tonnes of marine gas oil consumed on voyages
  • its total fuel consumption relating to in-port activities
  • the emission factor for marine gas oil
  • its total annual emissions of CO2, CH4 and N2O from its maritime activities

After you submit your emissions monitoring plan application

Pay the emissions monitoring plan application fee

After you’ve submitted your application, METS will add a task in your work queue to pay the emissions monitoring plan application fee.

This fee will also cover the cost of:

  • opening a maritime operator holding account in the UK ETS Registry
  • appointing an authorised representative with a surrender only permission to operate it for you

The Environment Agency’s UK ETS charges are set out in the Environment Agency (Greenhouse Gas Emissions) Charging Scheme.

You can pay by credit or debit card using GOV.UK Pay. You can also pay by bank transfer. This takes a longer to process.

Contact etmaritimehelp@environment-agency.gov.uk if you have problems paying.

How the Environment Agency assess your application

The Environment Agency will assess your application and contact you if they need more information in order to determine it.

When the Environment Agency has approved your application, they’ll issue your emissions monitoring plan in METS.

Your emissions monitoring plan sets out how you must monitor and report your greenhouse gas emissions from maritime activities in line with the requirements of the Order. You must comply with the conditions of your emissions monitoring plan. 

You should read and understand your emissions monitoring plan. The introductory note and conditions explain how to comply with UK ETS requirements.

Making changes to your emissions monitoring plan

You must regularly review your emissions monitoring plan to make sure it accurately reflects:

  • the operation of each of your ships
  • your procedures and monitoring methods
  • your internal risk assessment processes

The conditions of your emissions monitoring plan set out when and how it must be varied.

Changes to an emissions monitoring plan are categorised as either significant or non-significant.

How to vary your emissions monitoring plan

All changes to your emissions monitoring plan must be submitted through an application in METS. You may also apply in METS at any time to make any changes or amendments you consider necessary.

You must make your application to vary in METS by selecting ‘Start a new Task’ and then selecting ‘Start an Emission Plan Variation’. In your application to vary you must:

  • include a description of the change
  • set out how the change affects the information contained in the emissions monitoring plan

After you have submitted your application, the Environment Agency will consider your application to vary your emissions monitoring plan. They may ask you for more information in order to determine your application. They will determine your application within 2 months of receiving all the required information.

Significant changes

Any significant changes to the emissions monitoring plan must be made at least 14 days prior to making the change or, where this is not practicable, as soon as possible afterwards. 

Significant changes include:

  • adding a ship
  • adding new fuels or emissions sources, including sustainable fuels
  • changing a monitoring method
  • changing an emission factor value
  • changing the emissions monitoring plan holder’s name or address
  • intending to use eligible fuels that may form the basis of an emissions reduction claim
  • using or changing use of the exemption from per-voyage monitoring and reporting
  • using or changing use of carbon capture and storage
  • any change that may have a significant material effect on the monitoring and reporting of emissions from maritime activities

Non-significant changes

Non-significant changes to your emissions monitoring plan must be made by 31 December in the year they occur. If you anticipate several non-significant changes in the same year, you can submit them together in one application.

Examples of non-significant changes include:

  • removing a ship
  • updating any procedures in your emissions monitoring plan
  • any other change that is not a significant change that may affect the monitoring and reporting of emissions from maritime activities or detrimentally affect our ability to contact the emissions monitoring plan holder

Monitoring and reporting before your emissions monitoring plan is varied 

You can monitor and report on the basis of the proposed variations to your emissions monitoring plan before the Environment Agency has approved them if:

  • the proposed change is not significant
  • your current emissions monitoring plan would lead to incomplete emissions data

If you consider your current emissions monitoring plan would lead to incomplete emissions data, you must monitor and report based on both:

  • your current emissions monitoring plan
  • a revised version of your emissions monitoring plan containing the proposed variations

You must document all your emissions monitoring until the Environment Agency have approved the proposed variation to your emissions monitoring plan.

If you’re unsure whether a change is significant, contact etmaritimehelp@environment-agency.gov.uk as soon as possible.

If you do not comply with the conditions of your emissions monitoring plan, including conditions relating to changes, you may receive a civil penalty.

How the Environment Agency can vary your emissions monitoring plan

The Environment Agency can vary your emissions monitoring plan if they consider:

  • the variation is necessary because of your improvement report
  • you failed to comply with the conditions in your emissions monitoring plan that require you to apply for or make the variation
  • the variation is necessary to give proper effect to the Order

Monitor your greenhouse gas emissions

You must monitor your greenhouse gas emissions from your maritime activities from 1 January to 31 December in each scheme year that you’re a maritime operator. The first scheme year runs from 1 July to 31 December 2026, so you will only need to monitor during this period in the first scheme year.

Your monitoring requirements are set out in your approved emissions monitoring plan, which details any supporting written procedures. The rules about how to monitor and calculate your emissions are set out in Parts 4, 5 and 6 of Schedule 2A of the Order.

Your maritime emissions are your emissions of CO2, N2O or CH4 (which we refer to collectively as greenhouse gases) from maritime activities in ships that you are responsible for under UK ETS. Emissions from maritime activities are expressed in CO2 equivalent. Your maritime emissions figure will take into account any successful emissions reduction claim you make arising from an eligible fuel.

You will use the data collected during your monitoring to produce your annual emissions report. You must verify and submit the annual emissions report by 31 March in the year following the scheme year. 

Prepare and submit your annual emissions report

The task to complete your annual emissions report will appear in your METS work queue on 1 January each year, or on 1 July in the first scheme year. This task contains the annual emissions report form.

Your annual emissions report is available all year round to allow verification activities to be spread across the year. The reporting deadline is 31 March in the year following the scheme year.

You can submit verified annual emissions reports to the Environment Agency between 1 January and 31 March in the year following the scheme year. When the submission window opens on 1 January in the year following the scheme year, a button will appear that allows you to submit your annual emissions report.

If you do not submit your annual emissions report on time:

  • the task will show as overdue
  • the Environment Agency will determine your emissions and may charge you for this
  • you may be liable to pay a civil penalty for failing to report

You cannot amend the annual emissions report once submitted. If you become aware of an error in an annual emissions report, contact the Environment Agency.

You should start preparing early to make sure you are ready to submit your report by 31 March in the year following the scheme year. This is so that you:

  • have enough time to choose and appoint an independent verifier
  • allow your verifier enough time to perform the verification
  • can work with your verifier to correct any errors or misstatements in your annual emissions report
  • can submit your report and verification report to the Environment Agency by the 31 March deadline

What your annual emissions report includes

The annual emissions report form in METS is designed to ensure you include all the information required for UK ETS. 

You must include the following information for each ship:

  • total amount of each type of fuel consumed
  • aggregated greenhouse gas emissions from all in-port activities at ports of call
  • aggregated greenhouse gas emissions from all voyages between UK ports of call, other than those between Great Britain and Northern Ireland
  • if applicable, aggregated greenhouse gas emissions from all voyages between Great Britain and Northern Ireland

You must include the following information at operator level:

  • details of any emissions reduction claim arising from eligible fuels
  • details of any applicable surrender deduction
  • total maritime emissions
  • if you have a surrender deduction, your emissions figure for surrender, which is your maritime emissions less any surrender deduction

There is an option in METS to provide Voyages and Ports Data. You can use this to help you calculate your aggregated emissions, but there is no obligation to do so. Alternatively, the aggregate emissions can be provided for each ship manually or via XML upload. Your data supplier may also offer the option to transfer the data in automatically via an API.

How to make an emissions reduction claim  

Under the UK ETS, the eligible fuels set out in the Direction given by the UK government are treated as having an emissions factor of zero.

If you are a maritime operator purchasing an eligible fuel, you may be able to make an emissions reduction claim for the CO2 emissions from that fuel. A successful emissions reduction claim will reduce your maritime emissions figure and the number of allowances you need to surrender. 

You must include any emissions reduction claim in your verified annual emissions report submitted in METS.

To make a successful emissions reduction claim, you must meet all the following criteria:

  • the fuel you have purchased is an eligible fuel
  • the purchase has taken place in the scheme year or in the 3 months before the start of the scheme year
  • the eligible fuel has been delivered to a point of no return – for example, to a ship or a port fuelling system – by 31 March in the year following the scheme year
  • a declaration of no double counting, which is available in METS, must be downloaded, completed and then uploaded in METS – this is to confirm that you have not used the eligible fuel included in the emissions reduction claim to get an emissions reduction or financial benefit in relation to another scheme year, or in any other scheme, or sold by you to a third party

You must provide all documents required to support your emissions reduction claim to your verifier so that it can verify your emissions reduction claim in your annual emissions report. For each batch of eligible fuel claimed, you must submit: 

  • proof that the fuel is an eligible fuel
  • proof of purchase
  • proof that the eligible fuel has been delivered to a point of no return
  • the mass of the eligible fuel, or its volume and density so that its mass can be calculated
  • a declaration of no double counting

If you have met the emissions reduction claim criteria for a batch of eligible fuel, the Environment Agency will treat this fuel as having an emissions factor of zero. This will reduce the maritime emissions figure in your annual emissions report.

If your verifier is not satisfied that you have met all the criteria for a batch of fuel included in your emissions reduction claim, it must not verify that part as satisfactory. The claim relating to that batch will be rejected and the related fuel will be treated as having its default emissions factor.

The Environment Agency will also review emissions reduction claims. If all or part of your emissions reduction claim is rejected:

  • the Environment Agency will determine your maritime emissions
  • this may result in an under-surrender and a failure to surrender penalty

Appointing an independent verifier

All annual emissions reports must be verified by an independent verifier accredited by the UK Accreditation Service (UKAS). When you submit your annual emissions report by 31 March in the year following the scheme year, you must also submit your verifier’s verification report.

There is a list of UKAS accredited verifiers for UK ETS maritime operators in METS. After you have appointed a verifier, you can assign them to your METS account under the ‘Users and contacts’ tab. Choose the ‘Appoint a verifier’ option from this page and pick the appropriate verifier from the ‘Select a verification body’ drop-down list.

You should engage your verifier as soon as you are performing maritime activities as they will then be able to review your data throughout the year.

To maintain the independence of the verification process, the UK ETS verifier that is verifying your annual emissions report must not have any other relationship with you that could create a conflict of interest.

Verifier site visits

Site visits are an important part of the annual verification process. Without a site visit, your verifier may not be able to verify your annual emissions report as satisfactory.

In-person site visits

The site visit takes place where you manage your monitoring and control of relevant data and information. Your verifier will gather evidence and test the effectiveness of internal processes and control procedures. They may also interview staff.

Your verifier will carry out a risk analysis and decide how to conduct the site visit. You must allow access to any sites your verifier wants to visit. As data is often centralised, your verifier may decide that it is not necessary to visit every ship or location where information is stored.

Virtual site visits

Your verifier may carry out a virtual site visit instead of attending in person if:

  • they have carried out a risk analysis and are satisfied that a virtual site visit would provide reasonable assurance that your annual emissions report is free from material misstatements
  • you have applied to the Environment Agency (including the risk analysis) by 28 February in the year after the scheme year that your annual emissions report relates to
  • the Environment Agency has approved your application

The emissions plan holder must submit its application for approval to carry out a virtual site visit to etmaritimehelp@environment-agency.gov.uk.

When approving your application, the Environment Agency may set conditions that you must comply with, such as carrying out an in-person site visit for the following scheme year.

You do not need to produce and submit a new risk analysis, unless this was a condition of the approval, if both:

  • the Environment Agency approved a virtual site visit for a scheme year
  • no relevant circumstances have changed in future scheme years

Improvement reports

You will receive a task in your METS work queue if your verifier:

  • identifies any non-conformities in your annual emissions report
  • recommends any improvements to your monitoring and reporting

A non-conformity occurs when your annual emissions report does not follow your emissions monitoring plan or comply with the requirements of the Order.

Your recommended improvements may include:

  • your risk assessment
  • your data flow activities, control activities and any related procedures
  • the way you monitor and report emissions

You must complete your improvement report in METS. It must describe how and when you will:

  • address the non-conformities
  • implement the recommended improvements

When to submit your improvement report

You must submit your improvement report in METS by 30 June in the year you submitted the related annual emissions report, unless the Environment Agency has set an alternative date.

If you assert in your improvement report that recommended improvements would not improve the monitoring methodology, you must justify this. If you assert that the costs of making the recommended improvements would be unreasonable, you must provide evidence to support this.

As a result of the comments from your verifier, you may need to apply in METS to vary your emissions monitoring plan.

You do not need to submit an improvement report if, by 30 June in the year in which you submitted your annual emissions report, you have already:

  • addressed all non-conformities and recommended improvements identified by your verifier
  • applied for any related variations to your emissions monitoring plan

Your maritime operator holding account

A maritime operator holding account is a compliance account in the UK ETS Registry. It is used to record emissions figures and receive, hold and surrender allowances.

The only allowances that can be held in the UK ETS Registry and used for compliance in UK ETS are UK allowances.

You will need to purchase allowances to meet your surrender obligation. 

To surrender allowances from your maritime operator holding account, you only need one authorised representative with surrender-only permission.

You may also use your account to transfer allowances to other UK ETS Registry accounts. To be able to perform these transfers, you must apply to appoint at least 2 authorised representatives with a combination of permissions that enable them to initiate and approve transfers.

There is a charge to appoint additional authorised representatives. Nominated authorised representatives must undergo due diligence checks, including criminal records checks in some cases.

How to operate your maritime operator holding account

When the Environment Agency issues your emissions monitoring plan, they will create a maritime operator holding account for you in the UK ETS Registry. The registry administrator will then email your relevant METS contacts with the maritime operator holding account details and explain how to appoint an authorised representative.

The registry administrator may also ask you to appoint a UK ETS Registry primary contact to:

  • give instructions on your (the account holder’s) behalf
  • nominate an authorised representative to operate the maritime operator holding account

The registry administrator will ask you for information to determine whether your nominated authorised representative is fit and proper to perform their proposed role in the UK ETS Registry.

If satisfied the fit and proper test is met, the registry administrator will approve the nomination and give the authorised representative access to your account.

Your maritime operator holding account default settings

When your maritime operator holding account is created it will have the following default settings:

  • surrender by one authorised representative
  • transfers of allowances out of your account are only permitted to accounts on your trusted accounts list
  • a transfer to another account requires 2 authorised representatives – one to propose and one to approve the transfer

Contact the registry administrator at etregistryhelp@environment-agency.gov.uk to change these default settings.

Authorised representative permissions

An authorised representative can have the following permissions on a maritime operator holding account:

  • surrender allowances
  • propose actions
  • approve actions
  • approve actions proposed by another authorised representative
  • review account information only

You must get approval from the registry administrator to change an authorised representative’s permission. Some changes will require additional due diligence.

You must maintain your maritime operator holding account by making sure that:

  • you have an authorised representative
  • your contact details are up to date
  • as a minimum, you always have an authorised representative with a surrender permission in order to meet your surrender obligation

Surrender allowances in the UK ETS Registry 

Your surrender obligation

If you carried out maritime activities in a scheme year, you will be a maritime operator in that scheme year and you must surrender allowances equal to your emissions figure for surrender. You must do this from your maritime operator holding account in the UK ETS Registry by the surrender deadline.

The surrender deadlines are:

  • 23:59 UK time on 30 April 2028 for the 2026 and 2027 scheme years
  • 23:59 UK time on 30 April in the year following the scheme year from the 2028 scheme year onwards

You must surrender allowances equal to your emissions figure for surrender by the surrender deadline, even if:

  • your emissions figure for surrender has not been recorded in your account
  • you think the recorded figure may be incorrect

Your emissions figure for surrender is your maritime emissions minus any surrender deduction. You must surrender one allowance for each tonne of CO2 equivalent in your emissions figure for surrender.

The 50% surrender deduction only applies to voyages between ports of call in Northern Ireland and ports of call in Great Britain, which comprises England, Scotland and Wales. You must monitor and report all maritime emissions on these voyages but you only need to surrender for 50% of those emissions.

Your verified emissions figure for surrender will be recorded in your maritime operator holding account after the 31 March reporting deadline.

If you are unsure how many allowances to surrender, contact the regulatory team as soon as possible at etmaritimehelp@environment-agency.gov.uk.

Buying allowances

You will need to purchase allowances to meet your surrender obligation. You must make sure you have enough allowances available in your account to surrender by the deadline.

You can purchase allowances and have them delivered to your maritime operator holding account in the UK ETS Registry at any time after it has been opened. The registry administrator will provide your account number when it invites you to appoint an authorised representative.

You do not need to have an authorised representative on your maritime operator holding account to receive allowances.

You should arrange to purchase and receive allowances well in advance of the surrender deadline. It can take time to identify a suitable seller, complete due diligence, agree contracts, arrange payment and complete delivery.

You must allow for the transaction delays and transaction windows in the UK ETS Registry.

Allowances are created by the UK ETS Authority and introduced into the market primarily through auctions. Most UK ETS participants purchase their allowances on the secondary market from:

  • a person with a trading account in the UK ETS Registry
  • the holder of an operator holding account, an aircraft operator holding account or a maritime operator holding account in the UK ETS Registry

Check the list of UK ETS Registry Account Holders from whom you may be able to purchase UK ETS allowances.

The Environment Agency and the registry administrator are not permitted to recommend anyone who sells allowances.

If you do not surrender sufficient allowances by the surrender deadline, you will be liable to the Excess Emissions Penalty of £100 multiplied by the inflation factor for each allowance you failed to surrender on time.

Transferring allowances

Transfers of allowances between accounts in the UK ETS Registry are subject to transaction windows and transaction delays, and are also affected by the trusted account rules and the settings on your account.

The transaction window and transaction delay do not apply to surrender transactions, which you can make at any time and take effect immediately.

The transaction window 

You can only start or complete a transfer of allowances between accounts during the transaction window, which is:

The transaction window applies to all transfers, including those to accounts on your trusted account list.

The transaction delay

All transfers of allowances are subject to a delay of one working day in addition to any delay resulting from the transaction window.

The transaction delay does not apply to transfers to accounts on your trusted account list.

Trusted account list

Transfers to accounts on your trusted account list are not subject to the transaction delay but can still only take place during the transaction window.

To avoid the transaction delay, the account that is receiving the allowances must be on the trusted account list of the account that is delivering the allowances.

All accounts belonging to the same account holder are automatically added to the trusted account list on each of its accounts.

To add an account to your trusted account list, you need 2 authorised representatives with the correct permissions to propose and approve the addition. The account will be added to your trusted account list within one working day.

You can increase the security of your account by using an account setting that only allows the transfer of allowances to an account on your trusted account list.

Failure to surrender sufficient allowances by the statutory deadline

You must ensure that you have allowances available in your account in order to surrender by the deadline.

If you do not surrender sufficient allowances by the surrender deadline, you will be liable to pay the excess emissions penalty. This is a mandatory civil penalty of £100 (multiplied by the inflation factor) for each allowance that you fail to surrender by the deadline.

The excess emissions penalty applies even if you surrender in full after the surrender deadline.

You must still surrender allowances equal to your emissions figure for surrender in addition to paying the excess emissions penalty.  

If you do not surrender any deficit of allowances, the Environment Agency can issue a Deficit Notice requiring you to surrender allowances equal to the deficit by a specified date.

If you do not comply with a Deficit Notice, you will be liable to pay the mandatory Deficit Penalty and may also be liable to a discretionary daily penalty.

If you surrender too many allowances

It is possible to surrender more allowances than the emissions figure recorded in your maritime operator holding account. You may need to do this if:

  • you do not submit an annual emissions report by the surrender deadline
  • there are concerns that the figure in your annual emissions report may not be accurate

If you surrender too many allowances by mistake, contact the registry administrator by emailing etregistryhelp@environment-agency.gov.uk as soon as possible.

In some circumstances you can reverse the whole surrender transaction if you request this within 14 days of its completion and before the surrender deadline. If you cannot reverse the surrender transaction, the over-surrendered allowances will show as a credit which can be used to meet any future surrender obligations.

What you need to do before the surrender deadline

You should allow plenty of time before the surrender deadline to:

  • check you have enough authorised representatives on your maritime operator holding account with the necessary permissions to surrender
  • check your authorised representatives will be available to surrender by the deadline
  • engage with one or more sellers to purchase allowances and make sure payments to the seller are made in time
  • confirm with your seller that the allowances will be received in your maritime operator holding account in time to surrender
  • make sure your seller has set up any necessary trusted account arrangements

The Environment Agency cannot extend the surrender deadline.

The registry administrator cannot expedite transactions or trusted account list applications in the UK ETS Registry.

Annual tasks and compliance deadlines 

For each scheme year in which you are a maritime operator, these are the dates of your important tasks:

  • 1 January – start your monitoring for the current scheme year
  • by 28 February – if applicable, apply to us for permission for your verifier to carry out a virtual site visit for the previous scheme year
  • by 31 March – submit your verified annual emissions report for the previous scheme year using METS. We will then instruct the registry administrator to record in your maritime operator holding account your emissions figure for surrender, which is your maritime emissions less any applicable surrender deduction
  • by 30 April – surrender the number of allowances equal to your emissions figure for surrender for the previous scheme year. You must surrender for both the 2026 scheme year and the 2027 scheme year by 30 April 2028
  • by 30 June – if applicable, submit an improvement report for the previous scheme year
  • by 31 December – update your emissions monitoring plan to reflect any non-significant changes in the current scheme year

If you do not agree with a decision made by the Environment Agency

If you do not agree with a decision made by the Environment Agency, contact etmaritimehelp@environment-agency.gov.uk to discuss it first.

Where you have a right of appeal against a decision of the Environment Agency, this will be set out in the notice containing the decision. The notice will also provide information about how to appeal. All appeals against the decisions of the Environment Agency are to the First Tier Tribunal.

If you have concerns about your verifier

If you have concerns about your verifier’s performance or a decision they have made, raise these with your verifier first. Accreditation rules require verifiers to have the opportunity to respond to complaints before the national accreditation body can intervene.

If you are still not satisfied, contact UKAS and the Environment Agency to inform them about your concerns.

Information published about your account

Certain information in the UK ETS Registry is published in line with the requirements of the Order. This includes:

  • information about open accounts and their account holders, including emissions and surrenders
  • detailed information about account holdings and transactions, including the names of account holders involved in transactions that are more than 3 years old

Information about authorised representatives and primary contacts will not be published.

Glossary

Emissions monitoring plan: a plan approved and issued by the regulator setting out how the maritime operator will monitor its emissions for the purposes of UK ETS   

Annual emissions report: a report of the maritime operator’s emissions for each scheme year that must be independently verified and submitted to the regulator by 31 March in the year following the scheme year 

Maritime operator holding account: a compliance account in the UK ETS Registry in which emissions figures for surrender are recorded and from which allowances are surrendered

Maritime operator: the entity legally responsible for complying with UK ETS obligations 

Registry administrator: the entity comprising the chief inspector, the Environment Agency, Natural Resources Wales, the Secretary of State and Scottish Environmental Protection Agency, that operates the UK ETS Registry; this role is currently performed by the Environment Agency

UK ETS Registry: the UK ETS online database in which UK allowances are created, held, traded and surrendered

Registered owner: is the person named on the ship’s certificate of registry issued in the State of primary registration 

Emissions reduction claim: a claim that may be made in the annual emissions report in respect of an Eligible Fuel which results in the application of an emissions factor of zero to the Eligible Fuel and a resulting reduction in maritime emissions 

UK allowance: a unit equivalent to 1 metric tonne of carbon dioxide equivalent (COe) which is held in the UK ETS Registry and used by participants to meet their UK ETS surrender obligations 

Humanitarian aid or assistance: an activity performed for humanitarian purposes which transports relief personnel and relief supplies such as food, clothing, shelter, medical and other items during or after an emergency or disaster, or the evacuation of people from a place where their life or health is threatened by an emergency or disaster to a safe haven

Immediate family: in relation to a person, their spouse, partner, children and parents

Search and rescue: the performance of distress monitoring, communication, coordination and search and rescue functions, initial medical assistance or medical evacuation, through the use of public and private resources, including cooperating aircraft, ships and other craft and installations 

Surrender deduction: a deduction from the maritime emissions figure to reflect the scope of UK ETS which is necessary to calculate a maritime operator’s emissions figure for surrender 

Significant change: any change to the operation of an emissions monitoring plan holder that, under the conditions of its emissions monitoring plan, requires it to make an application to the regulator to vary its emissions monitoring plan at least 14 days before making the change 

Non-significant change: any change to the operation of an emissions monitoring plan holder that, under the conditions of its emissions monitoring plan, requires it to notify and provide details to the regulator by 31 December in the year in which the change occurs

Maritime emissions: the emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from the maritime activities of a maritime operator  

Bunker delivery note: a document recording the details of fuel delivered to a ship

Scheme year: the period from 1 July 2026 to 31 December 2026 and then, from 1 January 2027, the period from 1 January to 31 December in each calendar year

THETIS-MRV: The Hybrid European Targeting and Inspection System

At berth: the period when a ship is securely anchored in a port while loading or unloading or hotelling, including the time spent when not engaged in cargo operations 

Hotelling: the period when a ship is securely moored or anchored in a port, but is inactive and not loading or unloading cargo

ISM Code: the International Safety Management Code established by the International Maritime Organization to ensure the safe operation of ships and prevent marine pollution

UK: comprises England, Northern Ireland, Scotland and Wales

Great Britain: comprises England, Northern Ireland, Scotland and Wales

A port: the waters on the landward side of the outermost permanent harbour works and any offshore installation that has an assigned United Nations Code for Trade and Transport Locations (UN/LOCODE) as of 1 April 2026

Ship-to-ship transfer: the process of transferring cargo directly between two ships positioned alongside each other either at anchor or moving slowly underway

Crew: all persons on board the ship to provide navigation and maintenance of the ship, its machinery, systems and arrangements essential for propulsion and safe navigation or to provide services for other persons on board

Voyage: any movement of a ship from its last berth or ship-to-ship transfer within one UK port of call to its first berth or ship to-ship transfer in the next UK port of call or on its return to the same UK port of call, without any intervening stop at a port of call outside the UK

Updates to this page

Published 22 June 2026

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