I have never rented out my horses out for a wedding rode one in my own. I would think you would to carry insurance. Personally I might do it for friends but I would be really careful about doing it for anyone else. My friends put together a little video session of horse weddings gone bad before I rode down the isle so I had the full picture of everything that could happen (yeah thanks guys like I need any more pre-wedding jitters) Although funny it really gives you an idea of all the things that can go wrong. Your horse needs to be ready for thing blowing in his face, dresses coming down his back end and touching his legs people on either side of him clapping and jumping around, flags blowing children running in front of him people possibly throwing rice or other such things at him, just to name a few. In all honesty you never know what another person is going to do around your horse, most weddings are going to have a bunch of people without horse experience possibly doing weird things cause they just don't know any better. I know mine sure did.