The UK Government wrote EU Regulation 261 into UK law at the end of the Brexit transition period in December 2020. The name of the new law is Regulation (EC) No 261/2004 (as amended by The Air Passenger Rights and Air Travel Organisers’ Licensing (Amendment) (EU Exit) Regulations 2019).” It can sometimes be referred to as “UK261.”
UK passengers enjoy the same rights as before. Except now, depending on where they are flying, they are protected by the UK law or the existing EU version. Additionally, compensation is now paid in UK Pounds rather than Euros.