Here there aren't height limits. Only talent limits.
(aside from the occasional harsh judgement from judges, but to be fair I hear more about that anecdotally from owners who think their unschooled horse with terrible paces being ridden by a sack of spanners should have won, than actual true bias...)
I have seen a Sec A win at Elementary (Affiliated) with a young rider. Talent all round is what is needed but young jockeys grow & need bigger ponies/horses not matter how talented the small ones are. By the time a rider has all the right attributes they have generally outgrown the 12.2hh.
Thanks for all the replies . So would I be able to compete my pony till his old it's just I got told by someone I wouldn't as when I got to a certain age I had to move on to horses to compete at higher levels with him.
You can compete in NATIONAL classes with any height of horse/pony. You can only compete in INTERNATIONAL classes as an adult, with a horse. No ponies. Has to be bigger than 148cm I think (been a while since I checked the rule so not sure of exact height limit).