Skip to main content

RWE energy code modification appeal

The Competition and Markets Authority (CMA) is considering an appeal brought by companies within the RWE group against Ofgem’s 1 May 2026 decision to reject a proposed modification to the Connection and Use of System Code (CUSC).

Administrative timetable

Date Action
19 October 2026 Statutory deadline for CMA decision
23 June 2026 Deadline for applications to intervene
19 June 2026 Deadline for GEMA reply (extended)
9 June 2026 Deadline for CMA to decide on permission to appeal
26 May 2026 Permission to appeal sought by RWE

Extension granted for GEMA’s response

12 June 2026: The CMA granted an extension for GEMA’s response to the Notice of Appeal. The revised deadline is 19 June 2026.

Appeal group appointed

9 June 2026: The CMA has appointed a group of 3 panel members to determine the appeal:

Permission to appeal granted

9 June 2026: The CMA has granted RWE permission to appeal.

Notice of appeal

26 May 2026: Companies within the RWE group (Gwynt y Môr Offshore Wind Farm Limited, RWE Renewables UK Limited and RWE Renewables UK Swindon Limited) have sought to appeal an energy code decision by Ofgem’s governing body, Gas and Electricity Markets Authority (GEMA) made on 1 May 2026 in respect of modifications to the Connection and Use of System Code (the CUSC).

CMP344 is a proposal to amend the CUSC to require the allowed revenue increases reflecting income adjusting events (IAEs) to be recovered under the Transmission Demand Residual Tariff only (and thus not passed on to generators). Ofgem rejected the proposed modification.

Contact

codemodificationappeal2026@cma.gov.uk

Personal data

The CMA may collect, use and share personal data for energy licence modification appeals made to the CMA under the Gas Act 1986. This includes processing personal data for the purposes of the UK General Data Protection Regulation and the Data Protection Act 2018.

For more information about how the CMA handles personal data, read our personal information charter.

Updates to this page

Published 28 May 2026
Last updated 17 June 2026 Show all updates
  1. Extension granted for GEMA’s response

  2. Decision to grant permission to appeal published

  3. First published.