Changing the Locks When You Move into a New Home

Think about the lifecycle of a typical set of house keys before they reach you. The previous owners may have lived there for a decade, lending keys to family members, letting contractors in, leaving a spare with a neighbour on Garratt Lane or handing one to a managing agent who passed it to a maintenance team. When the property sold, some of those keys were handed back — but some almost certainly were not. The estate agent's key safe may have been accessed by several sets of viewers. If the property was a rental, the landlord or letting agent may still hold a master. None of these people are necessarily dishonest, but you simply cannot verify who has what.

The only way to be certain that your new home is secure is a full lock change London locksmiths carry out at the point of handover. This is not about distrust — it is about the fact that security resets to zero the moment a new occupant moves in. Home insurers often ask, in the event of a claim, whether the locks had been changed since you moved in. If the answer is no, that can complicate matters. Changing the locks is also the moment to upgrade to a standard your insurer actually requires — many policies specify a 5-lever mortice deadlock to BS3621 on timber doors, and a 3-star TS007 anti-snap euro cylinder on uPVC or composite doors.

Most traditional Victorian and Edwardian terraced houses in Earlsfield — the kind you find along streets like Penwith Road or off Tranmere Road — have timber front doors fitted with two locks working in combination: a Yale-type nightlatch and a 5-lever mortice deadlock. Replacing both is a straightforward job for an experienced locksmith but is not a simple DIY task, particularly the mortice deadlock, which sits inside a pocket cut into the door edge.

If you are wondering how to install a mortise lock in a new door yourself, the honest answer is that it involves precise chiselling of the door edge and frame, careful alignment of the keep, and a good understanding of which grade of lock meets BS3621. A poorly fitted mortice lock can actually weaken a door rather than strengthen it. Our skilled locksmiths measure, fit, and test everything on site, leaving you with a full set of new keys and the confidence that the lock is both secure and insurer-compliant. We carry BS3621-rated 5-lever mortice deadlocks and quality nightlatch cylinders as standard, so there is rarely a need to wait for parts.

The majority of post-1990s homes in Wandsworth — and many converted flats in blocks throughout SW17 and SW18 — have uPVC or composite front doors fitted with a multipoint locking mechanism. This type of door does not use a traditional mortice lock. Instead, a single euro cylinder (the barrel you turn with your key) operates several locking points simultaneously: hooks, rollers, and bolts that engage up and down the door frame when you lift the handle and turn the key.

The critical vulnerability here is cylinder snapping — a technique where a thief snaps the cylinder in half using simple tools, gaining access in seconds. This is a well-documented problem across London and is precisely why insurers and security bodies recommend anti-snap, anti-pick, anti-drill cylinders that meet the TS007 3-star standard. A door lock replacement London homeowners actually benefit from means swapping the existing cylinder for a high-security TS007 3-star replacement — often a 10-minute job once you have the right cylinder, but selecting the correct size (measured in millimetres from the centre screw to each end) matters enormously. Our locksmiths measure on site and carry a range of sizes. If you have been let down by a poor-quality cylinder that came with the door, an upgrade at the point of moving in is exactly the right moment to fix it. For uPVC door lock repair London properties sometimes need — such as a handle that drops or a mechanism that will not engage properly — we can service or replace the multipoint mechanism itself, not just the cylinder.

[6] In the UK, changing the cylinder so old keys no longer work is less commonly offered as a standalone service than a full cylinder change, which achieves the same result more reliably and often for a comparable cost. So when people ask whether they need to change the lock on a new property, the practical answer for most UK homes is: replace the cylinder (and the full lock set if the existing hardware is old, damaged, or below the required security rating). A new cylinder means new keys from the outset, no question about what old keys may still operate the lock, and the opportunity to upgrade to a higher-security standard at the same time.

If you are moving into a leasehold flat, check your lease before instructing any work — some leases require the freeholder or managing agent's consent before changing communal door locks, though your own flat's internal front door is almost always your responsibility. If you are unsure, our team can advise on what is typically possible and talk through the options with you before we begin. For landlords and letting agents in the Wandsworth area preparing a property between tenancies, changing the locks between occupants is both best practice and, in many cases, a legal safeguard — the previous tenant's keys should never open the door for the next one. If you need a locksmith London landlords and agents rely on for quick turnarounds between tenancies, we are set up to respond the same day.

If you ever find yourself in the stressful situation of wondering what to do when you're locked out of your house on moving day — perhaps the previous occupant's keys do not work in the lock, or a key has been lost in transit — our 24 hour locksmith London service means we can reach you quickly, gain entry without damage where possible, and change the locks in the same visit. The right thing to do when you are locked out is to check for any other accessible entry points you are authorised to use, see whether a spare key is with a solicitor or estate agent, and if not, call a professional. We will ask you to confirm ownership or tenancy before beginning any work — that is standard practice and something any reputable locksmith will do.

Whether you are arranging a planned lock change on moving day or you are dealing with something more urgent — a lock that has failed, a door that will not open, or a situation where you need an emergency locksmith London can provide quickly — the process when you call 020 3757 5840 is the same. We take the details of your situation, confirm the address (we cover Earlsfield, Tooting, Balham, Wandsworth Town, Putney, and surrounding areas in SW London), and give you an exact up-front price before anyone sets off. The factors that go into that price are the type of lock involved, the parts required, the time of day, and travel to your location — there are no hidden additions once work begins.

We send a locksmith straight away and are usually with you in around 30 minutes, though we will always give you a realistic arrival time on the call. As a 24/7 mobile service, we work evenings, weekends, and bank holidays — the times when moving delays and lock problems most often happen. We are insured, and our team is trained and experienced across the full range of residential lock types found in Wandsworth properties, from period timber doors to modern composite and uPVC. If you want the peace of mind of knowing exactly who can open your front door, call 020 3757 5840 — we answer 24/7.

Before the removal van arrives, it is worth running through a short list. First, budget for a lock change as part of your moving costs — it is a one-off security measure that pays for itself immediately. Second, check your buildings insurance documents for any requirements around lock grades; BS3621 and TS007 3-star are the two most commonly specified. Third, if you have a uPVC or composite door, ask us to check the euro cylinder size in advance if possible — it means we can ensure we bring the right parts. Fourth, if the property has a back door, patio doors, or French doors leading to a garden, include those in the conversation — rear access points are often overlooked but are a common entry route for opportunists. Fifth, if you are in a block of flats, establish early on who is responsible for the communal entrance lock and report any faults to the managing agent promptly.

Moving into a new home in Earlsfield or anywhere across the Wandsworth area should feel like a fresh start — and a lock change is the single most effective way to make it one. If you would like to book in a lock change for moving day, or if you are dealing with an urgent situation right now, our team is ready. Call 020 3757 5840 and we will sort it out.