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Energy Savings Opportunity Scheme (ESOS)

ESOS is a mandatory energy assessment scheme for organisations in the UK that meet the qualification criteria

Important changes to electronic payments: Our bank details have changed.

If you want to pay for your permit or licence application by electronic transfer please use the information below to make your payment. 

Company name:           Natural Resources Wales

Company address:       Income Department, PO BOX 663, Cardiff, CF24 0TP

Bank:                           RBS

Address:                      National Westminster Bank Plc, 2½ Devonshire Square, London, EC2M 4BA

Sort Code:                    60-70-80

Account number:         10014438 

Do not use the details given in our permit/ licence application forms and guidance if they are different to the ones above.

We will update our forms as soon as possible, but please use the new information when making electronic payments from now on.

Note: Waste mobile plant deployment application forms have been updated with the new information. 

Making payments from outside the UK

These details have changed.

If you are making your payment from outside the United Kingdom (which must be received in sterling), our IBAN number is GB70 NWBK6070 8010 014438 and our SWIFT/BIC number is NWBKGB2L. 

Send us your payment details by email

Please email your payment details and payment type details (such as ‘Waste Variation’ or ‘Water Quality New’) to or or fax it to 0300 065 3001.

You must include your company name and invoice number. Where possible, please also submit a remittance advice. This will ensure accurate processing of your payment. 

You should still include the BACS payment reference on the application form itself.

If you do not quote your payment reference number, there may be a delay in processing your payment and application. 

Organisations that qualify for ESOS must carry out ESOS assessments every four years. These assessments are audits of the energy used by their buildings, industrial processes and transport to identify cost effective energy saving measures. Each assessment is required to provide high quality and targeted advice to large undertakings on cost effective energy efficiency opportunities, which could lead to financial savings. 

Does my organisation qualify for ESOS?

You will qualify for ESOS if on 31 December 2014 you are:

1) An undertaking which has 250 or more employees in the UK

2) An undertaking which has fewer than 250 employees, but has: 

  • an annual turnover of €50m and 
  • a balance sheet exceeding €43m

3) Part of a corporate group, which includes an undertaking that meets either criteria (1) or (2) 

If you do not qualify for ESOS, you do not have to notify the Environment Agency or Natural Resources Wales.

What is an ESOS assessment?

In summary, an ESOS assessment is comprised of three elements:

  • A measurement of an organisation or corporate group’s total energy consumption over 12 consecutive months, covering the qualification date of 31 December 2014
  • An audit of at least 90% of the total energy consumption to identify cost effective efficiency recommendations. The audit must be conducted or at least reviewed by an audit “Lead Assessor” who is a member of a professional body approved by the Environment Agency
  • A review of the audit by a board-level director and approval of the audit by the Lead Assessor. For organisations that do not already do so as a matter of routine, ESOS provides a key opportunity to engage with board-level managers on energy expenditure and potential savings

If my organisation qualifies, what next?

Your organisation needs to read the full guidance on ESOS to understand the actions you need to take over the coming year to ensure you are in a position to comply by the compliance deadline of 5 December 2015. If you don’t already, you must immediately start collecting energy data to allow you to be in a position to comply. There are no registration forms to complete and no fees payable for participation. However, you must confirm that you have completed an ESOS assessment for your organisation by submitting a notification to the Environment Agency (the UK scheme administrator) by 5 December 2015.  The notification needs to be submitted via an online portal accessed from the ESOS web page.

What if my organisation doesn't comply?

If you fail to complete an ESOS assessment and/or do not notify compliance by the 5 December 2015 deadline your organisation will be at risk of enforcement action, including the possibility of civil penalties. Full details of the ESOS Assessment requirements can be accessed from the ESOS web page. 

How frequently should we complete ESOS assessments?

ESOS will operate in consecutive four-yearly compliance periods. The next qualification date for ESOS is 31 December 2018 with a requirement to notify compliance by 5 December 2019 for those that qualify. 

Further information

More detailed guidance on ESOS and how to comply can be found at If you can’t find what you are looking for please email the Environment Agency at regardless of whether your business is in England, Scotland, Wales or Northern Ireland. For all offshore related queries please email the Department of Energy and Climate Change at

What we do

Organisations must notify the Environment Agency by the set deadline that they have complied with their ESOS obligations.

Natural Resources Wales is the compliance body for undertakings registered within Wales. Our role includes:

  • Taking steps to monitor compliance with the scheme, including on-site inspections if necessary
  • Taking enforcement steps to bring organisations into compliance
  • Applying sanctions to undertakings that fail to come into compliance, with proportionate civil penalties

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