From the CAA:
Remote pilot minimum age requirement changes
28 January 2021 – The UK Government has now removed the minimum age requirement for remote pilots operating a UAS in the Open and Specific categories.
The competency requirements are unchanged, but from this date, the 12 years of age (Open category) and 14 years of age (Specific category) limits no longer apply.
Articles 9 and 9A of the UAS Implementing Regulation (EU 2019/947) have been deleted completely; the full details can be found in Statutory Instrument 2021 No. 10.
CAP 722, CAP 1789A and our factsheets (CAPs 2003-2008 and 2012) will be updated shortly.