Correct me if I'm wrong, but I suspect they mean "hiring" i.e. "for a fee" requires the licence... Again correct me if I'm wrong, but I had the distinct impression you guys weren't planning charging for this, were you? I'm pretty sure they can't do anything if you are doing it free. There hasn't been any laws passed that I am aware of that says you can't take your friends, family, friend of a friend, friend of a family member and their partners to a formal without holding a licence.
Defects are a different story though, they can do that either way, licensed or not.