ESOS NEWSLETTER – SEPTEMBER 2026 (ISSUE 45)

The latest ESOS newsletter from the Environment Agency confirms that the further progress update feature on MESOS is now live, with the second progress update due by 5 December 2026, and explains who must submit it and what information needs to be reported. The newsletter also provides an update on ESOS compliance rates and enforcement activity, alongside guidance on managing MESOS users and keeping account details up to date. In addition, it includes guidance on the rollout of GOV.UK One Login, including how to connect an existing MESOS account and what to do if sign-in details or two-factor authentication access have been lost.

MESOS Reporting System Update

The further progress update feature is now live in MESOS, allowing advanced users to submit their updates. You must have a registered organisation account in MESOS to do this.

To start and submit your further progress update, follow these steps:

Log in to MESOS
Select the ‘Accounts’ section.
Select your organisation account, then choose ‘start a new task’.
Under ‘Phase 3 Progress Update 2’, click the green ‘Start’ button.
The Progress Update 2 workflow will open.

Once started, ‘Progress Update 2’ will appear as a task on your dashboard. You can submit it within MESOS when it is complete, for your regulator to access.

The deadline for submitting your further progress update is 5 December 2026.

Submission of Further Progress Update

You must complete the second of the two progress updates if you are:

A responsible undertaking which submitted an initial progress update for the third compliance period under an existing MESOS account.
An undertaking that has left its highest parent group / participant following the submission of the initial progress update, which has not agreed to comply with its previous or new group so must comply on its own behalf as the responsible undertaking, under a new MESOS account.

Participants must report whether, since submitting their initial progress update, if they have implemented any further measures from their action plan or any measures not included in it. For each implemented measure, they must estimate the reduction in energy consumption achieved between 6 December 2025 and 5 December 2026. Participants may also optionally provide estimates for this period for measures previously reported as implemented in the action plan or initial progress update. The Environment Agency collates this data for publication of all progress updates on Energy Savings Opportunity Scheme – National Data Library.

Late submission or non-submission of the further progress update may result in enforcement action by your regulator.

Notification of Compliance and Action Plan data Q&A

What are the compliance rates for NOCs, action plans and initial progress updates?

More than 87% of ESOS participants now meet these requirements, with other organisations working to comply.

What is happening to organisations that have not submitted a NOC, action plan or initial progress update?

All organisations that qualify for ESOS must submit a NOC, action plan and initial progress update, even if their action plan does not propose any measures. Organisations that have not met these requirements are being investigated by the relevant compliance body and may face enforcement action.

the Environment Agency in England,
the Department of Agriculture, Environment and Rural Affairs in Northern Ireland,
the Scottish Environment Protection Agency in Scotland,
Natural Resources Wales in Wales
the Offshore Petroleum Regulator for Environment and Decommissioning for offshore undertakings.

If I have not submitted a NOC, action plan or initial progress update can I still do so?

Organisations that have not met these requirements may be at risk of enforcement action and should contact the Environment Agency immediately for advice on next steps.

MESOS User Management

Organisations should regularly review and update their MESOS contacts to keep information accurate and current. Removing outdated contacts, such as people who have changed roles or left the organisation, helps:

protect sensitive information,
avoid missed communications and
reduce the risk of unauthorised access.

Adding new users to the organisation account

Select ‘Users and Accounts’.
From the ‘add a new user’ dropdown, choose the user type you want to add: ‘Advanced User’ or ‘Restricted User’. Use the guidance link below the dropdown for help choosing the right role, then select Continue.
Enter the new user’s first name, last name and email address.
The new user will receive an email to confirm their identity and create their sign-in details.
Once they have completed this, change their status from ‘Accepted’ to ‘Active’ so they can sign in to the organisation account.

Disabling or removing a user from your account

Select ‘Users and Accounts’.
To disable a user, find their user line and change their account status to ‘Disabled’.
To remove a user completely, find their user line and select ‘Remove’.

GOV.UK One Login rollout to MESOS

As explained in recent newsletters, users must now sign in to MESOS using GOV.UK One Login. This is a secure way to access government services and will be rolled out across more services in future.

MESOS users will be prompted to connect their account to GOV.UK One Login when signing in if they have not already done so. Go to the MESOS sign in page and follow the steps in Annex A – One Login Guidance below.

Annex A – One Login Guidance

Connecting GOV.UK One Login to your MESOS account

Select ‘Start now’. You’ll be taken to GOV.UK One Login, where you can create a GOV.UK One Login if you do not already have one.
GOV.UK One Login will return you to the MESOS service.
Choose to connect your existing MESOS account to your GOV.UK One Login.
Confirm your identity using your MESOS sign in details.

Once connected, you’ll use GOV.UK One Login to access your MESOS account from then on.

If you have forgotten your MESOS sign in details

Resetting either a password or a two-factor authenticator app (2FA) for your MESOS account

During the process of connecting GOV.UK One Login to your MESOS account, you will be asked to enter your email address and confirm your identity using your existing MESOS password and 2FA.
If you need to reset your password, use the ‘I have forgotten or want to change my password’ link.
If you need to reset your authenticator app, use the ‘I have lost access to my authenticator app’ link.
You will receive an email which will allow you to reset either your password or your 2FA app. Please ensure that Junk/Spam folders are also checked for these emails.
If you still cannot sign in after following these steps, contact the ESOS IT helpdesk.

Resetting both the password and two-factor authenticator app (2FA) for your MESOS account

You must first reset one of the details, either your password or the 2FA app.
When you are asked for the other detail, select ‘I have forgotten my password and lost access to my authenticator app’.
You will be taken to the ‘Reset MESOS account password and authenticator app’ form.
Enter your name and the email address you use to sign in to MESOS.
Submit the form. You’ll get an email confirming that your request has been received. Once your request has been processed, you’ll get another email with a link and instructions on how to reset your MESOS sign in details. Please ensure that Junk/Spam folders are also checked for these emails.

Contact the Environment Agency (EA)

If you have any queries relating to ESOS or if there is anything specific you would like to see in future ESOS newsletters, please consult the ESOS Guidance in the first instance or email the EA's ESOS Technical Helpdesk.

For any IT specific queries relating to the MESOS Reporting System, please contact the EA's ESOS IT helpdesk.

ESOS NEWSLETTER – SEPTEMBER 2026 (ISSUE 45)