The horses, with multinational ownership, must be registered with FEI by 15 January 2020, under the name of the nation for which the horse will compete during the Olympic Games.
Example 1: a horse is owned by a French owner – who is registered as an owner in the FEI passport-, but is ridden by a Belgium rider. The nationionality of horse and rider is different, so it has to be adjusted by the national federation.
Solution: add the rider as an owner in the passport, and ask your federation to adjust the nationality. Problem solved!
Example 2: The horse is owned by a Belgium owner – who is registered as an owner in the FEI passport. The horse is ridden by a Belgium rider. The horse’s nationality is Belgium (because of his owner), so nothing to worry about!
Example 3: A horse is newly bought for the Olympics and it’s previous owner is still registered as the owner. If the previous owner has the same nationality as the rider, it’s not a problem. If the nationality is different, than hurry up and get it changed!