ECO1: Guidance for Suppliers


Publication date

Scheme name


These publications are for ECO1 reference only and apply to measures installed on or before 31 March 2015. For measures installed under ECO2 (1 April 2015 - 31 March 2017) please refer to the ECO2 Guidance.

The Energy Companies Obligation (ECO) is a government energy efficiency scheme for Great Britain, administered by Ofgem. Our guidance document provides guidance to suppliers on the requirements of ECO in accordance with legislation and our administrative processes.

The publication of updated guidance, ECO: Guidance for Suppliers (Version 1.2) follows the government's changes to the ECO scheme up to 2015, and Ofgem's subsequent ECO1.2 consultation.

Appendix 4 of Version 1.2 provides an overview of the amendments to the Order and subsequent changes to our guidance.

Changes to the ECO Order 2012 have now come into force, and Ofgem's ECO: Guidance for Suppliers supersedes all previous versions of our guidance for measures notified, or applications made, on or after 5 December 2014.

ECO 2015-2017 (ECO2) Guidance

The government has extended the ECO scheme from April 2015 until March 2017. Following our ECO2.2 consultation on the changes, we have now published our ECO2 Guidance for reference, alongside our response to this consultation. We have published this ahead of 1 April 2015 in order to provide industry with time to review the changes to ECO and make the appropriate preparations.

The ECO2 Guidance does not apply until the ECO2 obligation period commences on 1 April 2015. Until then, suppliers should refer to the ECO: Guidance for Suppliers (version 1.2), which is available below.

Previous versions of the guidance apply to measures notified, or applications made, before this date.

The table below lists the current and previous guidance documents and their respective dates of effect.

Document name

Document date of effect

Guidance for Suppliers (Version1.2) 5 December 2014 to 31 March 2015
Guidance for Suppliers (Version 1.1a) 1 May 2014 to 4 December 2014
Guidance for Suppliers (Version 1.1) 1 August 2013 to 30 April 2014
Guidance for Suppliers (Version 1.0) 1 May 2013 to 31 July 2013
Open letters (a series of five open letters) November 2012 to 30 April 2013