I only get one key,but it's always nice to know if they also leave a key with a neighbor or family member in case it's needed. I also keep my keys on colored keychains with the pets' names on them, never anything identifying the client. I keep them in a lockbox in my car so I don't forget one at home and I'm always prepared for a last minute booking. If the client requests the key back after the booking, I usually give them the keychain in hopes they use it again. If the client has a lockbox on site, it's best to leave the key there at all times. You never know who else they may have going in; i.e. friends, housekeeping svcs, maint persons, etc.