What Is a Deadlocking Night Latch?
A night latch — what most people call a Yale lock — is the small rim lock mounted on the inside face of your front door. When the door closes, a spring-loaded latch bolt snaps into the keep on the door frame, holding the door shut. The problem with a standard night latch is that this bolt can be pushed back with a credit card, a knife blade, or any thin flexible tool. In South London, this technique — called carding — takes under ten seconds and leaves no visible damage. Insurers and police refer to it as a low-force, no-damage entry method.
A deadlocking night latch adds an anti-thrust mechanism to the bolt. When the door is pulled shut, the main bolt locks rigid — it cannot be pushed, shimmied, or sprung. On a key-deadlocking model (like the Yale 85), you turn the key once to engage the deadlock. On an auto-deadlocking model (like the Yale 89 or ERA 235), the bolt deadlocks the instant the door closes — no key turn required. Both types are vastly more resistant to carding attacks than a standard latch. For anyone living in a mid-terrace or maisonette with an outward-facing timber door, upgrading is one of the most cost-effective security improvements available.
Deadlocking night latches are not the same as a standard night latch — they look similar from the outside but the internal mechanism is fundamentally different. They are also distinct from a Yale-branded lock, which is a family of products (Yale makes both standard and deadlocking models). For full door security, a deadlocking night latch is typically fitted alongside a BS3621 mortice deadlock lower on the door — the night latch handles day-to-day convenience while the mortice lock provides the insurance-grade deadbolt. For more security advice across South London, visit our Locksmith Advice hub or read about our team on the About Us page.
How to tell if you already have a deadlocking latch
Look for a small button or secondary bolt on the faceplate of the latch keep. If you also have to turn a key on the outside to double-lock it (rather than just pulling the door shut), you likely have a key-deadlocking model. If unsure, call us — a quick photo on WhatsApp is all we need to identify it.
Deadlocking Night Latch — Key Features
What sets a deadlocking model apart from a standard night latch
Anti-Thrust Bolt
When the door closes, the latch bolt locks rigid. No credit card, knife, or shim tool can push it back. The mechanism physically blocks lateral movement of the bolt.
Auto or Key-Operated
Choose key-deadlocking (turn key to engage) or auto-deadlocking (bolt locks the instant the door closes). Auto-deadlocking is the most convenient — no risk of forgetting to lock up.
Timber Doors Only
Designed for solid and engineered timber doors. Not suitable for uPVC or composite doors, which require multi-point locking systems. Perfect for Victorian and Edwardian terraces — the dominant housing type across South London.
From £250 Fitted
Supply and fitting from £250, including the lock, fixings, and a free security check. Upgrade from standard to deadlocking in under 45 minutes with no disruption to your existing door furniture.
Is a Deadlocking Night Latch Right for Your Door?
Most homes in South London have the wrong lock for their door type. Here's how to know if a deadlocking night latch is the right upgrade for you.
Good match if you have:
- A solid timber front door (Victorian, Edwardian, or 1930s terrace)
- A standard night latch that has never been upgraded
- A rental property where tenants need keyless egress but you want security
- A front door that is used multiple times daily (convenience is important)
- A home in a high-footfall South London street or with limited off-street security
Not the right choice if you have:
- A uPVC door — these need multi-point locking gearbox repairs, not rim locks
- A composite door — same issue; the lock is integrated into the multi-point system
- A fire door on an escape route — specific regulations apply; contact us for advice
- If your only goal is to satisfy insurer BS3621 requirements — you also need a mortice deadlock
⚠️ Fire Safety Note — Key Deadlocking Models
A key-deadlocking night latch requires a key to open from the inside when deadlocked. In a fire evacuation, if the key is not immediately to hand, this can delay escape. Auto-deadlocking models have a thumb turn on the inside that always allows exit without a key — making them the safer choice for most homes, and the type we recommend as standard. Always keep a spare key near the door if you have a key-deadlocking model.
Our Deadlocking Night Latch Services in South London
Supply, fit, repair, and emergency call-out — all at fixed prices
Supply & Fit
from £250We supply the deadlocking night latch and fit it on the same visit. Choose from Yale 85, Yale 89, ERA 235, Ingersoll SC71, and Union models. Includes door frame assessment and a free security check. Most jobs completed in under 45 minutes.
Like-for-Like Replacement
from £250Replacing a faulty deadlocking latch with the same model or a compatible upgrade. We carry common Yale and ERA spares on the van. If your latch failed overnight and you cannot get it to operate, this is the fastest fix.
Repair & Adjustment
from £120Stiff key, latch not catching properly, or the snib has dropped and locked the bolt? We diagnose and repair without unnecessary replacement. Often a matter of adjusting the keep position, lubricating the mechanism, or replacing a single spring component.
Emergency Lockout
from £120Locked out because your deadlocking latch has stuck, the snib dropped, or the key won't turn? We cover all of South London, 24 hours a day. Average arrival time under 30 minutes from your call. No damage entry where possible.
Which Deadlocking Night Latch Should You Choose?
The four models below cover the vast majority of South London homes. Each has a distinct mechanism and price point — here's what matters in practice.
85
Yale 85 Series — Key Deadlocking
Key-operated deadlockThe most widely sold deadlocking night latch in the UK. Turning the key from the outside engages the deadbolt; turning from the inside releases it. The inside snib can be set to hold the latch open (for daytime use) or allow it to fall. Suitable for: solid timber doors, 40–44mm thick. Available in brass, chrome, and white. Key consideration: without the thumb-turn upgrade, people can be trapped inside when deadlocked — we always recommend pairing with a thumb-turn cylinder on the outside or upgrading to the 89 series.
89 Recommended
Yale 89 Series — Auto Deadlocking
Auto-deadlockingOur most-fitted model across South London. The bolt deadlocks automatically when the door closes — no key turn required. Entry from outside requires the key; exit from inside uses a thumb turn (never requires a key). This eliminates the fire-safety concern entirely. British Standard variant available (BS 8621 compliant), meeting many insurer supplementary lock requirements. Also accepts an anti-snap cylinder upgrade on the rim cylinder for additional protection against cylinder attack.
235
ERA 235 Fortress — Auto Deadlocking
Auto-deadlockingA heavy-duty British-made alternative to the Yale 89. The ERA 235 uses a stronger case body than the standard Yale models and is popular in high-footfall properties such as HMOs and flats with communal entrances. Like the Yale 89, it auto-deadlocks on door close and has an inside thumb turn for keyless exit. Sold Secure Silver rated. We carry these on the van — typically available same day in South London.
Ingersoll SC71 — High Security
PremiumFor properties where maximum key security matters — solicitors, landlords, commercial-residential conversions. The SC71 uses Ingersoll's restricted keyway: keys cannot be cut at a hardware shop or key-cutting kiosk. New keys must be ordered through a registered Ingersoll locksmith, preventing unauthorised copying. Heavily constructed case, anti-pick cylinder, and anti-drill front plate. Price on request — typically 35–40% above standard models.
Not sure which model suits your door?
Send a photo of your existing lock on WhatsApp and we'll tell you exactly which deadlocking upgrade fits without modification. Rim latches are not universal — the backset, case size, and cylinder type all matter.
WhatsApp a PhotoHow It Works
From first call to fitted lock — usually under 90 minutes
Call or WhatsApp
Tell us your door type and current lock situation. We'll confirm whether a deadlocking upgrade is right for you, give you a fixed price, and arrange a time that suits — same day if needed.
We Arrive — On Time
Your locksmith arrives in a marked Locksmith South London van, with the recommended lock on board. We assess the door frame and existing keep before any work begins — no surprise extras.
Lock Fitted, Door Tested
The new deadlocking latch is fitted and tested from both sides before we leave. We check that the deadlock engages correctly, the keep is properly aligned, and — if requested — show you how the thumb turn and snib operate.
Why Choose Locksmith South London?
South London-based, no call-out fee, fixed prices — here's what that means in practice
DBS Checked & Fully Insured
We are police-checked and carry full public liability insurance. You can verify our ID card on arrival.
No Call-Out Fee
We do not charge a separate fee just for arriving. You pay a single fixed price for the work, confirmed before we start.
30-Minute Response
South London-based. Most customers see us within 30 minutes of calling — not a national call centre dispatching from outside the M25.
BS3621 Lock Stock
We carry insurance-grade BS3621 mortice deadlocks on the van alongside night latches — one visit covers both if you need the full upgrade.
Free Security Audit
Every job includes a walk-round check of your ground-floor locks. We tell you what's vulnerable — no obligation to buy anything.
Card, Cash & Bank Transfer
We accept all payment methods — no cash-only awkwardness on the doorstep.
5.0 Google Rating
Rated 5.0 on Google by verified South London customers. Read the reviews — most mention speed, price transparency, and not being ripped off.
Workmanship Guarantee
If the lock we fit develops a fault due to our installation, we return and fix it at no charge.
Deadlocking Night Latch Fitting Costs in South London
Fixed prices. No call-out fee. No VAT. Confirmed before we start.
Why no competitor publishes prices: most locksmiths quote by phone and inflate on arrival. We list our prices so you know exactly what to expect.
Supply & Fit — Standard Deadlocking
Yale 85, ERA 235, or equivalent. Lock supplied and fitted on the same visit.
- Lock included
- All fixings included
- Free security check
Supply & Fit — Auto Deadlocking (Yale 89)
Yale 89 or ERA 235 Fortress. Auto-deadlocks on close — thumb turn exit.
- Lock included
- Fire-safe (thumb turn exit)
- Free security check
Emergency Lockout
Locked out of your home because a deadlocking latch has jammed, the snib dropped, or the key failed.
- 24/7 availability
- 30-min arrival
- No damage entry where possible
High-Security Upgrade (Ingersoll SC71)
Restricted keyway, anti-pick cylinder, heavy-duty case. Send door photos for accurate quote.
- Restricted keys — no unauthorised copies
- Anti-drill front plate
- HMO and commercial use
All prices include VAT. After midnight — prices increase, call for quote. Prices confirmed before work starts.
What Our Customers Say
"My front door had a standard Yale that anyone could have slipped open with a card — I only found out when the locksmith explained it after my neighbour got burgled. He upgraded me to a Yale 89 on the spot. The whole job took about 40 minutes. No drama, no upsell."
David W.
Streatham, SW16
"Got locked out at 10pm because I had an older key deadlocking latch and the snib dropped. Locksmith was at my door in under 25 minutes. Once inside he explained exactly why it happened and showed me how to prevent it. Replaced the latch with an auto-deadlocking model — haven't had a problem since."
Amara P.
Croydon, CR0
"I'm a landlord with four flats in Norbury and wanted to upgrade all the front door night latches to deadlocking models between tenancies. They came out, assessed all four doors, and quoted me a flat price per door. Fitted ERA 235s on each one in the same afternoon. No mess, no cancellations."
Marcus B.
Norbury, SW16
Frequently Asked Questions
Common questions about deadlocking night latches — answered by your South London locksmith.
What is a deadlocking night latch?
Key deadlocking vs auto-deadlocking — what’s the difference?
Is a deadlocking night latch enough for home insurance?
Can a deadlocking night latch be fitted on a uPVC door?
How much does it cost to fit a deadlocking night latch in South London?
What happens if the snib drops and locks me inside or outside?
Related Lock Types
Also Serving Across South London
Explore the site
Locations we cover
Need a Deadlocking Night Latch Fitted in South London?
Stop a carding attack before it happens. We supply and fit deadlocking night latches across South London — same day, fixed price, no call-out fee.
Fixed prices · 30-min response · No call-out fee · Available 24/7
24/7 emergency locksmith serving South London since 2015 — trusted by homeowners, landlords and businesses across Sutton, Mitcham, Wallington, Cheam, Purley and surrounding areas.