I have been half leasing for quite some time. Sometimes we have a written agreement, sometimes not, but if I was leasing out my horse, I would definitely have a written agreement. I know there are some online, so googling something like "legal agreements for half leasing a horse" or what ever , might get somehting.
Basically, you have the monthly fee and what it includes and excludes. What day it's due on.
What happens if horse becomes unrideable .
In this case, unless it's a long time , like three weeks or more, we considered it bad luck and that the leasee must suck it up and pay. I have had plenty of times in the years I have been leasing that the hrose was unrideable for two weeks due to this or that problem and I never even asked to have my money back. I would not consider it unless it was happening a lot , in which case I would terminate the lease. It is not just renting. You are taking a part of the horse so much accept part of the risk, too.
Medical bills and liability
you must make clear who will pay medical bills in the event of an accident.
I always said that if it was something that happened due to my negligence, I would be liable for the bill. If it was something that just happens, like a stone bruise, or an abcess, it is not my liability, but I have always chipped in when the vet was needed. And if horse coliced, I was there to walk her or hang with her til vet came.
The more you make yourself useful the more you will get along , but if you are really new to this, you will have to ask if you can be helpful.
Shoes, ? Extra $ or included in lease agreement.
# of days you can ride per week?
Phone numbers of vets and emergency contacts.