https://www.caa.co.uk/commercial-ind...alent-licence/
https://www.caa.co.uk/Commercial-ind...d-from-the-UK/
https://www.caa.co.uk/media/nn3be5xc...ce-holders.pdf
Good luck! My understanding is that if more than five years out of date but you are current EASA you don’t need to do an initial but can regain CAA by doc transfer (SRG1217. Check the flow chart attached). Do some searching - there’s already plenty of info on this on this site.