When Should Locks Be Changed?

The question usually comes up after something has already gone wrong. A key has gone missing, a tenant has moved out, the door has started sticking, or there has been an attempted break-in. That is usually when people ask when should locks be changed. The honest answer is not on a fixed schedule. It depends on risk, wear, who has had access, and whether the lock still meets current security standards.

Leaving an old or doubtful lock in place can be a false economy. A lock might still turn, but that does not always mean it is secure. In many cases, changing the lock is less about convenience and more about reducing the chance of a burglary, failed insurance claim, or a call-out at the worst possible time.

When should locks be changed after moving in?

If you have just moved into a house or flat, changing the locks is usually the sensible option. You do not know how many spare keys exist or who still has one. Previous owners, former tenants, tradespeople, neighbours, cleaners, or family members may all have had access at some point.

This is one of the clearest situations where a lock change is worth doing straight away. For homeowners, it gives certainty from day one. For landlords, it helps protect the property between tenancies and avoids arguments later if access becomes an issue.

In some cases, rekeying may be discussed as an alternative, but often a full replacement makes more sense, especially if the hardware is old, low grade, or not up to British Standard. If the existing lock is not insurance compliant, moving in is a good time to put that right.

Lost keys, stolen keys and unknown access

If a key has been lost and there is any chance it can be linked to your address, change the lock. The same applies if a bag, set of keys, or work pass has been stolen. Waiting to see if anything happens is a risk most people regret taking.

There is a big difference between losing a key somewhere completely untraceable and losing one with identifying information attached. But even without an address label, many people are not comfortable knowing a stranger may have their key. That is reason enough.

For landlords and commercial premises, the risk is often wider. A former occupier may have copied a key without permission. Staff changes can leave uncertainty over who still has access. If there is no reliable key control, replacing the lock is often the cleanest way to reset security.

After a break-in or attempted break-in

Any break-in, attempted break-in, or visible damage around the door should trigger a proper inspection. Sometimes the lock is obviously broken. Other times, it still works but the cylinder, handle, strike area, or door alignment has been weakened.

This matters especially with euro cylinder locks on UPVC and composite doors. A cylinder that has been snapped, twisted, or attacked may not fail immediately, but it may no longer offer proper resistance. Replacing it with an anti-snap, British Standard option is usually the right move.

It is also worth remembering that burglars do not always need to force their way through a completely failed lock. If the mechanism is compromised, the property may remain vulnerable even after the door is shut again. A fast repair and lock replacement can restore security properly rather than just making it look closed.

When locks are worn, stiff or unreliable

Locks do wear out. That does not mean every stiff lock needs changing the same day, but repeated signs of trouble should not be ignored. If the key is hard to turn, the handle has become loose, the lock only works if you lift the door, or the mechanism is catching regularly, there is usually an underlying issue.

Sometimes the fault is the lock itself. Sometimes it is the gearbox, multipoint mechanism, door alignment, or worn hardware around it. On UPVC doors in particular, people often assume they need a new lock when the real problem is a failed mechanism or dropped door. The opposite also happens - a failing lock is left too long because it still works some of the time.

A proper assessment matters here. If the issue is wear and tear, replacing the right part early is usually cheaper than waiting for a complete lockout. Emergency access in the rain at 10pm is never the best moment to deal with a lock that has been warning you for months.

When should locks be changed for landlords?

For rental properties, lock changes should be considered at every change of tenancy, after evictions, after disputes over access, and any time key control has been lost. This is not just about caution. It is about protecting the next tenant, the landlord's liability position, and the building itself.

There are also practical reasons. Void periods are the best time to upgrade weak hardware, fit compliant locks, and deal with worn doors before a new tenant moves in. Once a property is occupied, a small lock issue can quickly become an urgent one.

For HMOs, offices and managed buildings, access control becomes even more important. If several people have come and gone over time, nobody can honestly say how many copies are out there unless a restricted key system is already in place. In that case, changing locks or moving to better-controlled hardware may be the more secure long-term option.

Insurance and security standards

One of the most overlooked reasons to replace a lock is insurance compliance. Some policies expect external doors to have specific standards in place. If your lock is outdated, damaged, or below the required grade, it could become a problem after a claim.

That does not mean every old lock is automatically invalid. It does mean you should not assume an ageing cylinder or basic night latch is good enough just because it still opens the door. If your insurer expects British Standard hardware or anti-snap protection and the property does not have it, changing the lock is a sensible upgrade.

This is particularly relevant after moving in, after a burglary, or when buying an older property that has never had its door security updated.

Business premises and staff turnover

For small businesses, schools, shared offices and public-facing buildings, locks should be changed whenever access control becomes uncertain. That might be after a member of staff leaves on poor terms, after contractors have had broad site access, or after a missing key is not recovered.

In these settings, delay creates a bigger problem. The more people involved, the harder it is to know whether the risk is real. A replacement lock, restricted key system or master key review can often solve the issue quickly and with far less disruption than people expect.

It is not always a case of replacing every lock in the building. Sometimes one external door, one plant room, or one office needs attention. The right approach depends on how the property is used and who needs access day to day.

Change or repair - which is the better call?

Not every faulty lock needs full replacement. If the issue is door misalignment, a worn keep, a failed gearbox, or a damaged handle set, a targeted repair may restore proper security. That can be the most cost-effective answer, especially on UPVC doors where the lock and the mechanism are separate parts.

But if the lock is obsolete, below standard, physically damaged, or tied to lost key risk, replacement is usually the better option. The key point is not to guess. The right diagnosis saves money and avoids repeat visits.

A well-stocked locksmith can usually tell on site whether the problem is the cylinder, the mechanism, the alignment, or the whole assembly. That matters because replacing the wrong part does not improve security. It just adds cost.

Signs it should not be put off any longer

If you are unsure whether to act now, a few warning signs usually mean do not wait. The lock has been forced, the key has gone missing, the door only locks with effort, the hardware is loose, the mechanism is grinding, or you cannot account for who has copies.

The same applies if you have just taken over a property and want certainty from the start. Peace of mind is not a small thing when it comes to front doors, staff access, or empty buildings.

For urgent situations, speed matters. For planned replacements, choosing the right lock matters just as much. A proper fit, the correct grade, and hardware suited to the door will always outperform a rushed swap with whatever is cheapest.

If you are asking the question, there is usually a reason. Trust that instinct, get the lock checked properly, and sort it before it turns into a bigger security problem.