Any athlete or horse who wishes to compete at an international level must first be a member of Eventing Ireland and the horse/pony registered with Eventing Ireland. They must then apply for an FEI licence and registration which is managed by HSI and information can be found on the HSI website here: https://www.horsesportireland.ie/passports/ and here: https://www.horsesportireland.ie/team-ireland-equestrian/fei-passports/
Also, in relation to Ponies, they must have an official FEI Height Measurement of 148cm (149cm with shoes). To learn more about this see the answer to the next question.
