If You just got the keys to a house you bought.
Then Rekey every exterior door to one new key.
The seller, their agent and any tradesperson who held a copy are now locked out, and you carry a single key. Lock Rekeying

Locks for shops, offices and buildings: rekeying at turnover, commercial-grade hardware, exit devices, master key systems and access control.
Services here appear in the order a business tends to need them: a lockout or a lost key first, then rekeying, then a master system, then exit hardware and access control as the premises grow and the staff list lengthens.
Commercial RekeyingA break-in overnight took the cash float and a staff member's bag with her work keys inside it.
Master Key System DesignA property manager taking over a small commercial building inherits a shoebox of keys with no labels and no chart.
Access Control InstallationSomething went missing from the storeroom over a weekend, and when you ask who was in the building, the honest answer is anyone…
Panic & Exit HardwareSomeone at the front counter always has to unlock the side door by hand before the lunch rush, because the round doorknob out…
Commercial-Grade Lock ReplacementA new tenant moved into the unit next door, and the property manager just found three different cylinders on three doors, none of…Tap a situation. The answer opens here.
If You just got the keys to a house you bought.
Then Rekey every exterior door to one new key.
The seller, their agent and any tradesperson who held a copy are now locked out, and you carry a single key. Lock Rekeying
If You are renting, and the landlord says the locks were never changed.
Then Ask the landlord to have the locks rekeyed.
Tenants generally need the owner's agreement, and most landlords are glad to do it when asked plainly.
If A tenant moved out and did not return every key.
Then Rekey before the next tenant arrives.
It keeps the same hardware and closes the gap before viewings start. Lock Rekeying
On-site assessment preferred · (365) 651-9607, open 24/7