School/lesson horses do not jump up to 1.50. They are usually confidence givers and work up to small jumps. You would need to purchase or lease your own horse (who has the ability to jump that high) in order to jump 1.50m. It also depends on you, 1.50 is big and you have to make sure you are able to keep yourself on. Horses that jump that high are usually powerful.. mine is!
I don t live in the Uk. Usually trainers do not have school horses that can jump up to 1.50