What is ECOES?

ECOES is a market information system supporting the electricity customer transfer process in Great Britain.

Rules and procedures relating to ECOES can be found in the MRA Agreed Procedure 15 .

Who Can Access ECOES?

  • A Supplier or Distribution Business who has commenced Market Scenario Testing;
  • Price Comparison Websites; and
  • Any other party,  which can demonstrate a benefit to the domestic electricity market from being granted access.

How to Apply for ECOES Access

Suppliers or Distribution Businesses will be provided with access to ECOES during Market Scenario Testing. Appropriate documentation will be sent during this process.

Any other party, except Price Comparison Websites, must complete the ECOES application process shown below.

To apply for ECOES access, please download, complete and return to the CAS helpdesk the following documentation:

Please contact the CAS helpdesk or call 0207 090 1024.

Price Comparison Websites are required to complete a different Access Agreement and Application Form. Please contact the CAS helpdesk as above, for further details.


The ECOES Privacy Policy and Terms of Use can be accessed below, to enable users to understand their obligations when using ECOES. Please note going forward the ECOES system will only include security updates, all other changes will only be made on the ECOES2 system.


The ECOES Application Programming Interface (API) is now available for MRA Parties to sign up to. The latest version of the Technical Specification is below:

ECOES API Technical Specification

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.