When buying a house, you should rekey the locks because you cannot be sure who else has keys to your new home, including the previous owner, contractors, or real estate agents, which could potentially compromise your security; rekeying allows you to control who has access to your property by creating a new set of keys only you possess. Key reasons to rekey a lock when buying a house: Security: The most important reason is to ensure only you have access to your home by eliminating the possibility of anyone else having a working key from the previous owner. Peace of mind: Knowing that only you have keys to your home provides a sense of security and peace of mind. Cost-effective: Rekeying is generally less expensive than replacing all the locks completely. Control over access: You can choose the level of security you want by selecting the type of key and lock combination when rekeying. Deterrence against burglary: Potential burglars may be less likely to target a home with recently rekeyed locks. .