You have a choice as to how you get your online renters to identify themselves:
This is the least onerous for your clients. Just say who they are with a minimum of fuss.
Great when you don't expect too much repeat business.
Your clients will register an actual account with which they can return and login.
It does require them to either:
- supply a password at the time of creation
- OR don't supply a password, but use 'forgotten password' if they want to log in again.