BIM24335 | Meaning of trade: mutual trading and members clubs: community amateur sports clubs: conditions for registration
From HM Revenue & Customs · Business Income Manual
What is a community amateur sports club?
You should refer any application to be accepted as a community amateur sports club to Specialist PT (Charities).
A club may be registered as a community amateur sports club where it meets the conditions below (Part 13 Chapter 9 Corporation Tax Act 2010):
it is open to the whole community
it is organised on an amateur basis, and
it has as its main purpose the provision of facilities for, and the promotion of participation in, one or more eligible sports.
For more information about CASCs see here.