That is a problem. If you last it you have to have tools and when the post man opens the mail box you remove the lock and go to a lock smith and have a new key made then install the lock. If a person loses the key we charge them $25.00 and do what l just told you. Plus we get a key for back up. Now you can go the your landlord and see if they have an extra key. If they do then you get another key made and return the original key. You just saved about $22.00