Changing the Locks When You Move into a New Home

Think about everything that happened before you collected your keys. The previous owners may have handed copies to family members, dog walkers, or cleaners. The selling agent almost certainly had a set. If the property was rented before it was sold, a letting agent or housing association may have kept a master key on file. None of these people are necessarily dishonest — but none of them have a reason to flag that they still have access to what is now your home. A lock change London on completion day closes that gap completely, without any assumptions having to be made about anyone.

There is also a practical insurance angle. Many home insurers ask that front doors carry a British Standard 5-lever mortice deadlock marked BS3621, or — on uPVC and composite doors — a TS007 3-star rated euro cylinder. If the existing locks do not meet that standard, you may find a claim is complicated or reduced. Getting a professional to assess and upgrade the locks on day one means your cover is in good order from the start, rather than something you get around to later.

Traditional timber front doors in Streatham — the kind you find throughout the streets running off Streatham High Road, up towards Streatham Hill, and around the Common itself — typically carry two locks working together: a Yale-type nightlatch near the top, and a 5-lever mortice deadlock lower down. The nightlatch handles the everyday pull-and-go convenience; the mortice deadlock is the security anchor. When a locksmith talks about a door lock replacement London, on a timber door this usually means swapping both mechanisms so that all previously issued keys become useless overnight. The nightlatch cylinder is replaced, and the mortice lock body — which sits inside the door — is either re-keyed with a new cylinder or replaced entirely with a BS3621-rated model if the existing one does not meet the standard.

Back doors on these properties are often lighter panel doors, sometimes with a simple two-lever mortice or a rim lock. These are worth assessing at the same time. A skilled locksmith can advise whether upgrading to a 5-lever mechanism is worthwhile given how the door sits and how the frame is constructed, so you are not spending money unnecessarily but are also not leaving an obvious weak point at the rear of the property.

The majority of newer properties in Streatham, as well as many homes that have had their doors upgraded in the past twenty years, will have uPVC or composite front doors fitted with a multipoint locking system. These doors lock at several points along the frame when you lift the handle and turn the key — which makes them inherently more secure than a single-point lock — but they share a common vulnerability: the euro cylinder. Standard euro cylinders can be snapped with a cheap tool bought online in a technique that takes seconds and leaves no visible damage to the door. Cylinder snapping is well documented across South London, and it is the reason anti-snap cylinders exist. When carrying out a uPVC door lock repair London or a full cylinder swap on a composite door, a good locksmith will fit an anti-snap, anti-pick, anti-drill cylinder rated to TS007 3-star. This single change removes the most exploited entry method on this type of door entirely.

It is worth being clear about what does and does not need to change on a multipoint door. The multipoint mechanism itself — the gearbox and the hooks or bolts that engage the frame — rarely needs replacing unless it is worn or damaged. What needs to change is the euro cylinder, which is a relatively contained job: the old cylinder is removed by undoing a single securing screw and turning the key to release it, and the new one slots in and is secured. The new cylinder comes with a fresh set of keys, and the old ones stop working. If you are moving into a flat in a block, the communal entrance door — which may also be a uPVC or composite door with a euro cylinder — should be discussed with your managing agent or housing association, as they typically coordinate cylinder changes for shared entrances.

A professional lock change with Streatham Common Locksmith starts with a brief conversation about the door type, the locks already fitted, and your insurer's requirements if you know them. When a locksmith arrives — we operate as a 24 hour locksmith London service and are usually with you in about 30 minutes — they will inspect the door, the frame, and the existing hardware before confirming an exact price upfront. No work begins until you have agreed the quote. The job itself typically involves removing the old lock or cylinder, checking that the door and frame are in good condition (a poorly fitting door can undermine even a high-quality lock), fitting the new hardware, testing the mechanism thoroughly, and handing over the new keys. The whole process is straightforward for most standard doors and causes no damage to the door itself when carried out correctly.

It is also worth knowing what to do when you get locked out of your house before or during the moving process — a more common scenario than people expect when keys are being passed around between solicitors, estate agents, and removal teams. If you find yourself locked out London, the right steps are: check for a spare key with someone you trust, check whether any other entrance to the property is accessible and secure, and if neither is an option, call a professional locksmith rather than attempting anything yourself. A trained locksmith can gain entry to a deadlock or a multipoint door without damaging the door — a question we are asked regularly, and the answer is yes, the right tools and experience make non-destructive entry possible in most cases. What to do when you are locked out of your house is straightforward: do not attempt to force anything, do not call someone who cannot verify their credentials, and do not leave the property insecure while you wait. Call 020 4530 9860 and we will send someone straight out to you.

Not every door needs the most expensive lock on the market, but every door does need a lock that is appropriate for its type, its position in the property, and what your insurer expects. For timber front doors, a BS3621 5-lever mortice deadlock is the baseline a reputable locksmith will recommend, and it is specifically the standard most UK insurers reference. For uPVC and composite doors, a TS007 3-star anti-snap euro cylinder is the equivalent benchmark. Back doors, side gates into gardens, and French doors into reception rooms are worth reviewing at the same time — not to upsell unnecessary hardware, but because a chain is only as strong as its weakest point, and a motivated intruder will simply move around to the door that has had less attention.

There is also value in thinking about door furniture beyond the lock itself: letterbox restrictors, door chains, and door viewers all add layers without requiring major work. As an emergency locksmith London service, we see the results of break-ins regularly — and the properties that fare best are rarely those with the most expensive locks, but those where every potential entry point has had some considered attention. If you are unsure where your property stands, a security assessment at the same time as the lock change costs nothing extra and gives you a clear picture of what, if anything, needs doing beyond the front door.