Changing the Locks When You Move into a New Home

When a property is sold or re-let, the outgoing occupier hands over the keys — but only the keys they still have. Over the years a property might have had copies cut for a cleaner, a dog-walker, a family member who fed the cat, a previous letting agent's office set, or a builder who was given a key during a renovation and never returned it. There is no register of outstanding copies, and no way to track them down. The only reliable solution is to replace or re-cylinder the locks so that every key previously in circulation simply stops working. For most homes in Croydon this is a straightforward job that a skilled locksmith can complete in under an hour, and it means you go to bed on your first night knowing exactly who holds a working key to your home.

There is a secondary reason that matters from an insurance perspective. Many home contents and buildings policies require that your front door is fitted with a 5-lever mortice deadlock that meets British Standard BS3621. If the lock fitted is old, damaged, or below that standard, a claim could be complicated. Getting a professional lock change done at the outset — with the right grade of lock fitted — means your home is both secure and correctly specified from the moment you move in.

The two most common front door types across Croydon's residential streets are traditional timber doors and uPVC or composite doors, and they use quite different locking systems — so the work involved differs too. On a timber door you will typically find two locks: a Yale-type nightlatch (the one that clicks shut when you pull the door to) and a 5-lever mortice deadlock set into the edge of the door. Changing these means replacing the cylinder in the nightlatch and swapping out the mortice lock body. A skilled locksmith will ensure both are properly aligned, that the new 5-lever mortice meets BS3621 if it needs to, and that the door closes and locks smoothly. You end up with a small set of new keys that only you hold.

uPVC and composite doors — which are very common on newer Croydon properties and in blocks of flats — work differently. They use a multipoint locking system operated by a single handle, and the security-critical component is the euro cylinder: the barrel-shaped section that your key turns. Cylinders on uPVC doors are vulnerable to a specific attack called cylinder snapping, where an intruder snaps the cylinder in two and uses the broken piece to operate the mechanism. The solution is to fit an anti-snap euro cylinder, ideally one carrying the TS007 3-star rating, which is the UK's highest standard for cylinder resistance. A door lock replacement Croydon homeowners with uPVC doors should request is specifically an anti-snap, anti-pick, anti-drill cylinder — not simply any euro cylinder that fits the same size. At Addiscombe Locksmith we only fit cylinders that meet current UK security standards, and we measure and cut to the correct size on the visit so there are no exposed ends that make snapping easier.

[10] In the UK, the standard approach is to change the cylinder (on a nightlatch or a uPVC euro cylinder lock) or replace the entire mortice lock body (on a 5-lever mortice deadlock). This is what most people mean when they say 'change the locks', and it is the approach a locksmith Croydon residents can rely on us to recommend based on what is actually fitted to their door. Changing the cylinder means reshuffling the internal pins of a lock so it operates on a new key — it is the standard approach used in the UK, and it is clean and straightforward. For most Croydon homes, changing the cylinder or the mortice lock is the cleaner, more straightforward option, and it also gives you the opportunity to upgrade to a higher-security lock at the same time if the existing one is worn or below standard.

One question we are asked regularly is whether you need to change every lock in the property or just the front door. Our advice is to think about which doors give direct access from outside: the front door, the back door, any side gate access to a ground-floor flat, and any communal entrance where you have a key. If a previous occupier had a key to your personal flat door and to the communal entrance, changing only one of those is not a complete solution. We can assess each door on the visit and advise you on what is worth changing and what is not — there is no obligation to do more than is genuinely necessary.

Moving into a property sometimes uncovers issues that were not obvious during the viewing. uPVC doors in particular can develop problems with the multipoint mechanism over time — a handle that is stiff, a locking point that does not engage fully, or a door that has dropped slightly on its hinges so the lock no longer lines up with the keep. These are not just inconveniences; a multipoint lock that does not engage at every point around the door frame is significantly weaker than one that does. If you notice any of these issues when we visit for a cylinder change, our team can carry out a uPVC door lock repair at the same appointment rather than leaving you to arrange a second visit.

It is also worth knowing that if you ever find yourself locked out Croydon — whether on moving day itself because a key snapped in the lock, or at any point afterwards — a professional locksmith can usually open the door without damaging it, then carry out a lock change in the same visit. What to do when you're locked out of your house is a question we answer on the phone every day: check for an unlocked window or back door as a first step, let us know you are the occupier (we will ask for proof of address before carrying out any work), and call us on 020 4542 3118. We will send a locksmith straight away and are usually with you in around 30 minutes. We cover the whole Croydon area including CR0, CR2, CR7, and surrounding districts.

When you book a lock change, it helps to know the terms so you can have a confident conversation with the locksmith. For a uPVC or composite door, ask specifically for an anti-snap euro cylinder with TS007 3-star certification — this is the highest residential cylinder standard in the UK and is recognised by most insurers. Make sure the cylinder is sized correctly for your door (too long and the exposed spindle becomes a snapping handle; too short and it may not operate the cam properly). For a timber front door, ask for a 5-lever mortice deadlock to BS3621 and a quality nightlatch cylinder. If your door has a letter box, it is worth asking about a letter-box guard as well — letter boxes on timber doors are a known entry point for fishing attacks where tools are pushed through to manipulate the handle.

At Addiscombe Locksmith we are a 24 hour locksmith Croydon residents and landlords call for everything from emergency lockouts to planned security upgrades. When you call us to book a lock change, we will ask about your door type and the locks currently fitted, explain what we recommend and why, and give you an exact price before we travel — the final cost depends on factors such as the door type, the grade of lock chosen, and the time of call, but you will always know the figure before anyone leaves for your address. There are no hidden additions when we arrive. If you are a landlord with multiple properties in the Croydon area, or a letting agent arranging a lock change between tenancies, we are equally happy to discuss what works best across a portfolio.

Moving day is chaotic at the best of times, and it is one of the more common occasions when people find themselves locked out of their house. Keys go into the wrong box, removal crews prop doors open and they click shut, or a lock that was already on its last legs finally gives up. What to do when you get locked out of your house on a day like that is simple: do not attempt to force entry yourself, and do not leave a window open as a temporary workaround — that is an invitation to opportunist theft while your attention is on the removal van. Instead, call our emergency locksmith Croydon team on 020 4542 3118. We operate 24/7 including weekends and bank holidays, so it does not matter whether it is a Saturday morning or a late Sunday evening — we will be on our way.

A professional locksmith will open the door using non-destructive techniques wherever possible, meaning the door and frame stay intact. We will then talk you through your lock-change options on the spot so you can decide whether to upgrade at the same time. This is exactly the kind of situation where having a local, experienced locksmith number saved in your mobile makes the difference between a 30-minute delay and a much more stressful afternoon. Save 020 4542 3118 before moving day — we are your Addiscombe Locksmith team, and we are always available.