Key lock boxes are often mentioned by other professional pet sitters. They don’t cost a lot, and when you only want the pet sitter to have your house keys while you are on vacation this is a great idea for the key pick up. Your pet sitter only needs the keys while you are gone, but I wouldn’t keep the keys stored in the lock box for the duration of your vacation. However, the benefit of a pet sitter having an extra key is if you get locked out of your house.