There a many reasons locks need to be changed. Because they are the first line of defence against intrusion your locks need to be kept at maximum efficiency, and that means being able to offer the highest levels of security.
MOVING TO A NEW HOME
Moving home can be an expensive business and it is tempting to try to save wherever possible on further costs. But without exception, changing the locks on your new home as soon as possible is always advisable. Even if the locks are fairly new and in perfect working order, the security they can offer is still compromised. It is impossible to know how many keys are in circulation and who has them. Often homeowners will give trades people they trust keys whilst working on their home. Even if these are trustworthy, sub-contractors may not be. Homeowners regularly leave duplicate keys with neighbours in case they lock themselves out. Again, whilst these neighbours may be trustworthy, they are just as liable to lose keys as anyone else. Rather than risk keys having fallen into the wrong hands, it is always better to have new locks fitted.
WEAR AND DAMAGE
It may seem obvious, but a lock that shows signs of wear or damage should be replaced as soon as possible. A damaged or worn lock is less secure than one in good order. If a lock looks damaged, rusted or worn and does not function as it should with ease, get it changed.
It is easy to assume that losing a key when out will not compromise security. People often think that if the key was not attached to anything that would identify the address to which it gives access, losing it is a mere inconvenience. However, it is not beyond the realms of possibility for someone less than honest to see someone drop a key, pick it up, and follow the owner home.
It goes without saying that if you are unfortunate enough to have been burgled, your security is highly compromised and you will need to change all of your locks.
PEOPLE MOVE OUT
Whether it is a lodger, ex-partner or someone else who has been living with you, if they leave it is best to have any locks to which they held keys replaced.
If you think a lock is worn or others may have keys, change it.