Mortice Locks & Yale Nightlatches
Front doors across Wandsworth tell a familiar story: a Yale-type nightlatch handles the day-to-day coming and going, while a 5-lever mortice deadlock sits below it and does the serious security work overnight. Whether you live on a terraced street off Garratt Lane, in a first-floor flat near Earlsfield station, or in one of the newer conversions close to Wandsworth Town, the combination of these two lock types is still the most common arrangement our technicians encounter every single day. When either one fails, jams, or simply no longer meets your insurer's requirements, getting it sorted quickly and correctly matters.
Open 24 hours, 7 days a week · Fully insured
Earlsfield Locksmith is a mobile, 24/7 locksmith service covering the Wandsworth area. We come to your door — no shop, no waiting around. Our trained and insured technicians carry a wide range of British Standard and manufacturer-approved hardware on the van, so most mortice deadlock and nightlatch jobs are completed in a single visit. This page explains exactly what is involved in fitting and replacing these lock types, what affects the final price, and how to make sure the work is done to a standard your insurer will actually accept.
What we do
Available 24/7
Day, night, weekends and bank holidays — a real local locksmith answers and sends a fully-stocked van.
We come straight away
Based in Wandsworth, we send a locksmith straight away — we're usually with you in about 30 minutes.
Fully insured
Vetted locksmiths, a clear price on the phone, and no surprise add-ons when we arrive.
Damage-free entry
We pick and bypass locks the right way, so most lockouts are solved without drilling anything.
Why 5-Lever Mortice Deadlocks & Yale Nightlatches Are Still the UK Standard
A mortice deadlock sits inside a pocket cut into the door edge — the mortice — so it cannot simply be ripped off the face of the door. A 5-lever mechanism means there are five levers that must be lifted to precisely the right height before the bolt will move, making it considerably more resistant to picking than cheaper 2- or 3-lever alternatives. The British Standard for insurance-grade mortice deadlocks is BS3621. If your policy wording says your front door lock must meet BS3621 and it does not, a claim can be refused even if the lock was otherwise functioning. Our technicians check the standard marking on the lock case during every survey, and we only fit locks that carry the correct hallmark. Many households in Wandsworth upgraded their deadlocks following a wave of domestic burglaries recorded along streets in the SW17 and SW18 postcode districts in recent years — it remains one of the most practical steps a homeowner can take.
Yale-type nightlatches operate on a spring latch: the door pulls shut and latches automatically, with a key used from outside and a knob or lever from inside. The original design dates back well over a century and is still widely manufactured, but quality varies considerably. A thin-cased budget nightlatch offers very little resistance; a double-locking nightlatch — where the latch is deadlocked from outside using the key — is a meaningful step up. For a timber front door, using a double-locking nightlatch alongside a BS3621 five-lever mortice deadlock gives you the two-lock arrangement most home insurers expect. Our team carries both standard and double-locking nightlatch variants and will advise which is appropriate for your door thickness and frame condition.
Fitting and Replacing Mortice Locks & Yale Nightlatches: What the Job Actually Involves
Replacing an existing mortice deadlock begins with removing the old lock case, faceplate, and both escutcheon plates. If the previous lock was a different size, the mortice pocket may need to be enlarged or packed, and the door edge may need new chisel work to seat the faceplate flush. Our technicians take measurements before ordering or selecting a replacement, because fitting a lock that is even slightly too large for the mortice will weaken the door stile and potentially invalidate the installation. Where the door has shrunk or swollen due to age or weather — common on older timber doors in Wandsworth's Victorian and Edwardian terraces — the keep or striking plate on the frame may also need adjustment to ensure the bolt engages fully. A bolt that travels less than its full throw is a security weakness, and we do not leave a job until the throw is clean and complete.
Nightlatch replacement is generally quicker but still requires care. The backplate must be positioned so the cylinder sits centrally in the door and the connecting bar is the correct length — too short and the latch will not retract; too long and the mechanism binds. On older doors with multiple layers of paint or slight warping, achieving a clean, flush fit takes skill. Where possible we work damage-free, using existing fixings and holes, but on a door that has been poorly fitted previously we will explain clearly what additional work is needed before we begin. As a locksmith London service operating across Wandsworth, we also encounter composite and steel-faced doors that use a mortice case but with a different faceplate dimension to standard timber-door locks — we carry the appropriate variants for these too.
Emergency Locksmith London: Locked Out, Broken Keys, and Failed Locks
A seized mortice deadlock or a snapped nightlatch cylinder does not wait for a convenient moment. We receive calls from residents locked out of their homes in Earlsfield, Tooting, Balham, Wandsworth Common, and throughout the SW postcode area at all hours — evenings, weekends, and bank holidays included. As a 24 hour locksmith London service, we answer the phone around the clock and send a technician straight away; in most cases we are with you in roughly 30 minutes, though we will always give you a realistic arrival window based on where the nearest technician is at that moment.
When you call us during a lockout, our first step is to confirm ownership or occupancy of the property — this is a standard and necessary part of responsible locksmith practice. We will ask you to describe the property and may ask for identification on arrival. Our preference is always to open a door without damage where the lock and door condition allow it; if the lock or door has already been compromised and damage-free entry is not possible, we will explain this clearly and get your agreement before proceeding. After gaining entry, we assess whether the lock should be repaired or replaced and give you an exact, agreed price for any further work before we touch anything. For a 24 hour locksmith London call-out, the time of day, travel distance, and the parts required will all be reflected in the quote — which you will have in full before we begin.
Lock Change London: Getting the Specification Right for Insurance and Landlord Compliance
A door lock replacement London residents often overlook is not just about fitting any lock that fits the hole — it is about fitting the right lock for the right door to satisfy the right people. If you are a tenant, your letting agent or housing association may specify the lock standard required, and in some cases the landlord must approve any change. If you own your flat in a managed block, the managing agent may have requirements about communal door hardware too. Our technicians are experienced in navigating these situations and can supply written confirmation of the hardware fitted, including the BS standard, which you can pass on to your insurer, landlord, or managing agent.
For homeowners who have recently moved into a property in Wandsworth — particularly along roads like Allfarthing Lane or around the Southfields grid — changing the locks as soon as possible is strongly advisable. You have no way of knowing how many copies of the previous keys are in circulation. A lock change London service from our team means new hardware, new keys, and the reassurance that only the keys we hand to you on the day will operate the lock. We also carry out door lock replacement London-wide across the Wandsworth borough, including properties in Putney, Tooting Bec, and the streets around Wandsworth High Street, with no need to book days in advance for most standard jobs.
Pricing, Call-Out Charges, and What to Expect When You Call
We do not publish fixed price lists because the final cost of a lock fitting or replacement depends on several genuine variables: the type of lock specified (standard BS3621 five-lever, high-security anti-pick variant, double-locking nightlatch, and so on), the condition of the existing door and frame, any additional work needed such as keep adjustment or faceplate chiselling, the time of day — evenings, weekends, and bank holidays carry a different rate to standard daytime hours — and travel distance to your postcode district. What we commit to is giving you a complete, itemised price on the phone or on arrival, before any work begins. There are no hidden charges added afterwards. A call-out charge applies, and this will be included in the quote we confirm with you upfront.
If you are comparing what different tradespeople are offering, the most useful questions to ask are: what standard is the lock they propose to fit, is it appropriate for your insurer's requirements, and do they carry that hardware on the vehicle today? A trained technician who can answer those questions clearly and confirm an exact price before starting is what you should be looking for. Call 020 3757 5840 and we will talk you through the options for your specific door and situation — no obligation, no pressure.
Keeping Your Wandsworth Home Secure: Practical Guidance
Beyond fitting the right locks, a few habits make a significant difference to door security. Always use the mortice deadlock when leaving the house, not just the nightlatch — a latch can be slipped with a card or strip in a way that a fully thrown deadlock bolt cannot. If your nightlatch has a double-locking function, engage it every time. Check that the keep plate on the door frame is fixed with long screws that reach the structural timber behind the frame — short screws into a thin frame are common and are the reason many doors fail even with a good lock fitted. If your door shows signs of frame damage, rot, or misalignment, let our technician know when you call: a lock is only as secure as the door and frame it sits in.
Residents in Wandsworth's older housing stock — particularly the late-Victorian terraces that run between Garratt Lane and the River Wandle — often find that their doors have been modified multiple times over the decades, with redundant lock holes, filled pockets, and mismatched hardware. Our technicians assess each door individually and will not simply fit a new lock into a compromised situation without flagging the issue. Security starts with an honest assessment, and that is always the first thing we provide. To book a visit or get advice on your specific locks, call 020 3757 5840 — we answer 24/7 and a skilled, insured technician is always available to help.
Frequently asked questions
Does my mortice deadlock need to be BS3621 for my home insurance to be valid?
Many household insurers — particularly those offering policies in urban areas like Wandsworth — specifically require that front door deadlocks meet the BS3621 standard. The requirement is usually stated in the policy terms under the section covering locks or security conditions. If your existing lock does not carry the BS3621 marking, your insurer may reduce or decline a claim relating to a break-in. Our technicians check for this marking during every visit and only fit locks that meet the standard when an insurance-grade replacement is what you need. If you are unsure about your policy wording, it is worth reading it before we arrive so we can confirm the correct specification on the spot.
How is the price for a mortice lock or nightlatch replacement worked out?
The final quote depends on several factors: the type and grade of lock required, the condition of your existing door and frame, whether any additional work is needed such as adjusting the keep plate or enlarging the mortice pocket, the time of day your call-out takes place — evenings, weekends, and bank holidays are priced differently to standard daytime hours — and your location within the Wandsworth area. All of these are factored in and confirmed as a single, complete price before any work begins. There are no additional charges added once the job is underway. We always include the call-out charge in the upfront quote so there are no surprises.
Can you replace a lock in a rented flat in Wandsworth without the landlord's permission?
As a tenant you generally need your landlord's or letting agent's permission before changing the locks on a rented property, unless there is a specific safety reason — such as an abusive or threatening situation — that makes waiting impractical. In standard circumstances, the responsible route is to contact your landlord or letting agent first. If permission is granted and they want a copy of the new key, that is a reasonable and common request. We are experienced in working with both tenants and managing agents across Wandsworth and can supply written confirmation of the hardware fitted, which makes the process straightforward for all parties.
My nightlatch has stopped springing back — does the whole lock need replacing or just the cylinder?
A nightlatch that no longer springs back is usually a sign of a worn or broken latch mechanism inside the case rather than a problem with the cylinder alone. In many cases the entire lock case needs replacing, as the internal components are not designed to be individually serviced in the field. However, our technician will examine the lock on arrival and confirm exactly what is needed before any work is done. If only the cylinder has failed — for example it has become stiff, the key snapped inside it, or it has been visibly damaged — it may be possible to replace just that component and retain the existing case, which can reduce the work involved.
How quickly can you get to me if I am locked out in Earlsfield or Wandsworth at night?
We operate 24/7 and send a technician as soon as you call. In most parts of the Wandsworth area, including Earlsfield, Tooting, Balham, Southfields, and Wandsworth Town, we are usually with you in around 30 minutes. We will give you a realistic arrival window based on where our nearest available technician is at the time of your call, rather than quoting a time we cannot stand behind. Call 020 3757 5840 at any hour and someone will answer immediately.
What should I do while I am waiting for a locksmith if I am locked out?
The first thing worth doing is checking whether you have a spare key with a trusted neighbour, family member, or friend who could bring it to you. It is also worth checking whether any other entrance to the property is accessible — a back door, a window you know to be unlatched, or a communal entrance code if you are in a block of flats — but only attempt access through a route that is genuinely yours and that you can enter without causing damage. If none of these options apply, stay somewhere warm and safe — a nearby shop, a neighbour's hallway — and call 020 3757 5840. We will talk you through the situation on the phone and confirm an arrival window straight away. Do not attempt to force or bypass the lock yourself, as this risks damaging the door and can make the eventual job more complex and costly.