On 15 April 2026, Ofgem published a letter to all wholesale energy market participants and other interested parties setting out its concerns regarding the use of thresholds for the determination
of inside information under Article 4 of the Regulation on Wholesale Energy Market Transparency and Integrity (REMIT).
In particular, Ofgem is concerned with the way that a 100MW threshold is being applied in the British power market and its potentially adverse impact on market transparency. Ofgem also sets out specific expectations for Offshore Transmission Owners and highlight issues relating to certain non-balancing mechanism unit assets.
Key parts of the letter include:
- While we recognise that internal thresholds can serve a purpose for operational efficiency and timely publication, we have concerns with the way such thresholds appear to be applied and the impact this may have. For the avoidance of doubt, our position is that any fixed MW threshold is inherently unreliable under Article 2.
- We expect all market participants to review their procedures in light of the issues raised in this letter, namely that thresholds are an unreliable indicator of whether information is inside information, and that those applying a 100MW threshold in deciding whether to publish outage and availability information may risk failing to publish information in a timely and effective manner and thereby breaching Article 4 REMIT. As indicated, we recognise that internal thresholds can serve a purpose for operational efficiency, but we urge market participants to ensure that these are calibrated and applied appropriately and are advisory rather than strict, to ensure that all necessary information is published. Ofgem and PPATs will be monitoring this area closely and will take action where necessary. If market participants wish to communicate directly with us regarding this issue, including the outcome of reviewing their practices, please contact us at REMIT@ofgem.gov.uk.