On 21 December 2020, the EU Agency for the Cooperation of Energy Regulators updated its open letter of 8 January 2019 regarding data reporting under Regulation (EU) No 1227/2011 on wholesale energy market integrity and transparency (REMIT) following the end of the transition period. The purpose of the open letter is to give guidance to national regulatory authorities and to inform market participants and the wider market about the views of the Agency with regard to certain repercussions on the implementation of REMIT after the UK’s transition from the EU on 31 December 2020.