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Locksmith-Picked · Updated 2026

Best Locks for Wooden Doors UKTop 5 BS3621 Mortice & Night Latch Picks

No affiliate links. No paid placements. Five locks ranked by what real South London locksmiths actually fit, every week, on every kind of timber door — from Victorian terraces to 1950s post-wars.

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Every lock on this list has been pulled out of a Locksmith South London van and fresh fitted into a real Victorian, Edwardian, interwar or post-war timber door — sometimes more than once a week. This isn't a roundup of Amazon best-sellers. It's the working short-list.

The brief on this page is simple: which BS3621 locks actually deserve a spot on a wooden front door in the UK? Most "best of" articles you'll find are either affiliate-driven (the lock that pays the most commission ranks first) or written by someone who has never cut a fresh mortice into a Victorian stile. We do both for a living, so the criteria here are different.

For deeper context, read our main wooden door locks service page, the mortice lock guide for the deadbolt mechanism explained, the 5-lever mortice lock page for the BS3621 standard in detail, or the Yale lock page for the night-latch side. Insurance angle covered separately on BS3621 and home insurance. About the team: about us · contact us · areas we cover.

How We Ranked These Five Locks

  • BS3621 kitemark — non-negotiable. Every pick is certified.
  • Insurer recognition — UK home insurers must accept the spec.
  • Real-world fit quality — how often we see one fail or stick.
  • Spare parts availability — can we get a like-for-like keep plate, lever pack or replacement key fast?
  • Heritage door compatibility — does the case sit cleanly into a 1900s mortice without splitting the surround?
  • Fitted price honesty — total cost including labour, not just the eBay sticker.

One more thing before the list: a wooden front door wants two locks, not one. Every UK insurer policy you'll read sets the BS3621 mortice as the minimum. Pair it with a deadlocking night latch and you have the configuration we fit roughly nine times out of ten. The first three picks are mortice deadlocks; the fourth is the night latch we recommend; the fifth is a trade-grade alternative for landlords and HMOs.

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The Top 5 Ranked Picks

What We Actually Fit on South London Timber Doors

Five locks. Honest editorial order. Plain English.

1
Editor's Pick

Union 2134 BS3621 5-Lever Mortice Deadlock

Best Overall · Union (ASSA ABLOY)

The default recommendation on a South London Victorian or Edwardian front door. Union absorbed Chubb's domestic line years ago, and the 2134 is the lock that carries that legacy forward at a sensible fitted price.

Why it wins: Clean-cutting hardened plates, crisp lever pack, spare parts shipped next-day anywhere in the UK, and the faceplate kitemark is unambiguously present. We've swapped hundreds of these across Croydon, Dulwich and Forest Hill and the failure rate is negligible. The 76mm case version suits standard 44mm external timber doors; the 64mm is for slimmer period doors. Both carry the same BS3621 kitemark and insurer recognition.

KitemarkBS3621
Levers5
Case Sizes64mm · 76mm
Bolt Throw20mm
Fitted From£180

Strength

Parts availability. Clean kitemark. Consistent quality.

Watch For

Not the cheapest at retail — pay for the brand.

2
Best Value

ERA Fortress BS3621 5-Lever Mortice Deadlock

Best Budget BS3621 · ERA Home Security

The pick when budget is the constraint but insurance compliance isn't optional. ERA Fortress carries the full BS3621 kitemark at a noticeably lower trade price than Union or Chubb, and the build quality is still British-tested solid.

Why it's on the list: ERA is one of the UK's oldest lock brands and the Fortress line exists specifically for homeowners who need insurance-grade security without Chubb pricing. Fitting feel is slightly less crisp than Union — the bolt throw has marginally more play — but over five years on a standard door you'd struggle to tell them apart. Strong choice for rental properties and second homes.

KitemarkBS3621
Levers5
Case Sizes64mm · 76mm
Bolt Throw20mm
Fitted From£180

Strength

Full BS3621 spec at the lowest fitted cost.

Watch For

Slightly less tactile than Union at the handle.

3
Heritage Premium

Chubb 3G114 BS3621 5-Lever Mortice Deadlock

Best for Heritage Doors · Chubb (original)

The heritage pick. The 3G114 is the genuine original-spec Chubb case — heavier, longer-lasting, and the lock you want on a Grade II listed timber door where the deadbolt needs to still work in 2076.

Why we still recommend it: Chubb's domestic range is harder to source than it used to be (Union now owns the name), but the 3G114 mechanism is still produced and still carries the full BS3621 kitemark. The case weight is noticeably heavier than the Union 2134 — you can feel it in the hand — and the lever pack tolerances are tighter. Used by high-end period property restorers across London. Fitted rate is the same BS3621 mortice standard; Chubb-branded parts sourcing can add a nominal cost on top — send us your door details for a fixed quote.

KitemarkBS3621
Levers5
Case Sizes76mm
Bolt Throw20mm
Fitted From£180

Strength

Heaviest case. Longest service life. Heritage-appropriate.

Watch For

Harder to source same-day. Parts cost extra on top of the fitted rate.

4
Best Night Latch

Yale 89 Deadlocking Night Latch

Best Companion Lock · Yale

The night latch you want above a mortice deadlock. The Yale 89 is the deadlocking version — it throws a fixed bolt that can't be slipped with a credit card, and that single detail is what separates a serious front door from a decorative one.

Why it's here, not higher: A deadlocking night latch is a complement to a BS3621 mortice, not a replacement for it. On its own, the Yale 89 does not meet most UK insurer policy wording — you still need the kitemarked deadlock below. Paired with one of the top three picks above, this is the configuration we fit most often across South London terraces and semis. Yale's brand heritage is real; the 89 is the modern working version of their original 1960s night latch design.

TypeDeadlocking Night Latch
KitemarkBS3621 pair
BoltSprung + Fixed
CylinderRim, 6-pin
Fitted From£250

Strength

Anti-slip deadlocking bolt. Auto-locks on close.

Watch For

Needs a mortice deadlock below it for insurance.

5
Best Trade Pick

Asec BS3621 5-Lever Mortice Deadlock

Best for Landlords & HMOs · Asec / ABUS

Trade favourite for volume installs — HMOs, blocks of flats, landlord portfolios where the lock has to be fit-and-forget across dozens of doors. Asec carries the full BS3621 kitemark and costs less per unit than the branded alternatives.

Why it's on the shortlist: For a Victorian single-family front door we'd recommend Union or ERA first — the fitting feel and case weight are better. But for a 12-unit HMO or a block of converted flats where you need insurance compliance at scale and spare keys on fast turnaround, Asec is the pragmatic pick. The kitemark is the same; the insurer recognition is identical. The case tolerances are looser, which means slightly more bolt rattle over time — acceptable on a communal door, less ideal on your own front door.

KitemarkBS3621
Levers5
Case Sizes64mm · 76mm
Bolt Throw20mm
Fitted From£180

Strength

Insurance compliance at scale. Fast key turnaround.

Watch For

Slightly loose tolerances over 10+ years.

Side-by-Side

The Five Picks Compared at a Glance

Specs, kitemark status, insurance, and fitted prices on one page.

Lock BS3621 Levers Case Size Best For Fitted From
1Union 2134 Yes 5 64 / 76mm Overall best pick £180
2ERA Fortress Yes 5 64 / 76mm Best value £180
3Chubb 3G114 Yes 5 76mm Heritage / Grade II £180
4Yale 89 Pair — Surface Night latch companion £250
5Asec BS3621 Yes 5 64 / 76mm HMO / landlord £180
1

Union 2134

BS3621Yes
Levers5
Case Size64 / 76mm
Best ForOverall best pick
Fitted From£180
2

ERA Fortress

BS3621Yes
Levers5
Case Size64 / 76mm
Best ForBest value
Fitted From£180
3

Chubb 3G114

BS3621Yes
Levers5
Case Size76mm
Best ForHeritage / Grade II
Fitted From£180
4

Yale 89

BS3621Pair
Levers—
Case SizeSurface
Best ForNight latch companion
Fitted From£250
5

Asec BS3621

BS3621Yes
Levers5
Case Size64 / 76mm
Best ForHMO / landlord
Fitted From£180

Fitted prices include lock, labour, two new keys cut on site and 12-month workmanship guarantee. No call-out fee, no VAT add-on.

The Full Setup

What UK Insurers Actually Want to See on a Wooden Front Door

Ask any home insurance specialist and the answer is nearly identical: a BS3621 5-lever mortice deadlock as the primary lock, paired with a deadlocking night latch above it. Neither lock alone meets most policy wording. Together, they do.

The mortice handles the structural security — drill-resistant plates, 20mm bolt throw, hidden inside the door so there's no external fixing to attack. The night latch handles the daily-use convenience — auto-locks on close so the door is never left on the latch, with a fixed deadbolt that can't be slipped.

The insurance pattern

Read any UK home insurance policy schedule on a wooden door and the wording is close to: “all final exit doors must be fitted with a five-lever mortice deadlock conforming to BS3621.” The night latch sits above that as best-practice layered security recommended by both insurers and the Met Police's Secured By Design guidance.

For the complete insurer breakdown, see our BS3621 & home insurance guide, or the insurance approved door locks hub.

1 Upper Lock Daily Use

Yale 89 Deadlocking Night Latch — mounted at roughly 1600mm from the floor. Auto-locks when you pull the door closed. Deadbolt thrown from inside via thumbturn or from outside via key.

Covered by pick #4 above
2 Primary Lock Insurance-Grade

BS3621 5-Lever Mortice Deadlock — mounted at roughly 1000mm from the floor, set into the mortice cut-out on the door edge. Our editor's pick is the Union 2134.

Covered by picks #1, #2, #3, #5 above
3 Optional Extras Best Practice

Hinge bolts top and middle. Security viewer at eye height. Letterbox restrictor to prevent fishing attacks. Door chain or guard at chest height.

Included in our free audit
Mortice + Night Latch Combo Mortice from £180+Night Latch from £250 Send door photos on WhatsApp for an exact combined quote.
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Avoid These

Six Buying Mistakes We See Every Week

Common errors that turn a good lock purchase into an insurance claim headache or a wasted afternoon.

Buying a 5-Lever Without the Kitemark

Five levers is the mechanical count. BS3621 is the test certification. Plenty of eBay locks have five levers but no kitemark — they fail the insurance clause.

FixCheck the faceplate for the kitemark symbol plus "BS3621" stamp before you buy.

Wrong Backset Size

UK mortice locks come in 57mm and 76mm backsets. Order the wrong one and the new keyhole misses the existing escutcheon cut by 19mm.

FixMeasure from door edge to keyhole centre before ordering. If unsure, call us to measure for you.

Night Latch as Primary Lock

A Yale latch alone — even the deadlocking version — does not satisfy most UK insurer policy wording on a wooden front door. Claims have been refused on this.

FixFit a BS3621 mortice deadlock as the primary lock. Night latch is the companion.

Ignoring Door Thickness

External UK timber doors are 44mm. Internal are 35mm. A 76mm-case mortice lock fits 44mm cleanly but splits a 35mm door when installed.

FixMatch case depth to door thickness. 64mm case for slim doors, 76mm for full external doors.

Forgetting the Keep Plate

A new mortice in the door body but the original keep plate in the frame — common DIY mistake. The bolt doesn't align, the door feels loose, security is zero.

FixAlways replace the strike plate when changing a mortice lock. Kits include both.

Fitting Without Inspecting the Timber

Old doors split, swell or have soft fibres. Fitting a fresh mortice without checking the timber condition splits the stile and ruins the door.

FixTap the door edge, check for damp staining, probe suspect spots with a bradawl before cutting.
Fitting Services

We Fit Every Lock on This Page

Book a Survey

Single Mortice Fit

Union, ERA, Chubb or Asec BS3621 5-lever mortice deadlock fitted like-for-like. Two keys cut.

From £180

Yale 89 Night Latch

Deadlocking night latch fitted as companion lock above a mortice. Cuts cylinder slip risk to zero.

From £250

Full Combo Upgrade

BS3621 mortice + deadlocking night latch fitted together. The full insurance-compliant setup.

Heritage Chubb Fit

Chubb 3G114 sourced and fitted on listed or Grade II period timber doors where spec matters.

From £180 + parts
Why Locksmith South London

We Know Each of These Locks. We Fit Them Every Week.

The ranking on this page reflects years of actual fitting experience across South London's Victorian, Edwardian, interwar and post-war housing stock. Union, ERA, Chubb, Yale, Asec — all in the van today, all fitted hundreds of times on real doors.

6,000+BS3621 Locks Fitted
30 minAverage Response
5.0Google Rating

DBS Checked

Every locksmith DBS-cleared. Work across homes, schools and care settings.

No Call-Out Fee

Quote is the price. No travel charge, no out-of-hours surcharge, no hidden VAT.

30-Min Average

Vans staged across South London CR, SE, SW, SM and BR postcodes.

Fixed Fitted Prices

You hear the price before we touch a screw. No surprise add-ons.

Free Security Audit

One-page report on lock kitemark, hinge bolts, frame integrity and timber condition.

12-Month Guarantee

Workmanship and parts covered. We come back free if anything fails inside the year.

Card or Cash

Pay how you like. Card reader on the van. Receipt emailed before we leave.

5.0 Google Rating

Hundreds of South London homeowners. Verified reviews, not paid testimonials.

All Five Brands Stocked

Union, ERA, Chubb, Yale and Asec BS3621 kits in every common size on the van.

Heritage Timber Trained

We know how to cut a fresh mortice into a 1900s door without splitting the stile.

Verified Reviews

Homeowners Who Took Our Advice

5.0Google verified
“

Read this page before booking, asked for the Union 2134 specifically plus a Yale 89 above. Fitted on my 1890s Camberwell front door in one morning, insurer accepted the spec over email. No upselling, no drama.

OA
Olumide A.Camberwell, SE5
“

Listed Victorian house in Herne Hill, needed the Chubb 3G114 specifically to keep the conservation office happy. They sourced it in two days, fitted it in three hours, case fits like the lock that came out. Brilliant job.

CL
Clemmie L.Herne Hill, SE24
“

Manage a block of seven converted timber doors in Peckham. Wanted consistent kitemarked locks across all seven. Asec was the budget-friendly answer and the fitter did all seven in one morning. Invoiced against one PO.

YM
Yusuf M.Peckham, SE15
Heritage timber door with BS3621 mortice lock fitted — best locks for wooden doors South London
All Five Picks Stocked

Every Brand on This Page. On the Van. Today.

Union 2134 · ERA Fortress · Chubb 3G114 · Yale 89 · Asec BS3621

Common Questions

Best Wooden Door Lock FAQs

Real questions homeowners ask before booking. Short, direct answers.

What is the best lock for a wooden front door in the UK?
The best single lock for a wooden front door is a BS3621-certified 5-lever mortice deadlock. The Union 2134 is the locksmith's most-fitted choice, followed by ERA Fortress and Chubb 3G114. For a complete setup, pair the mortice deadlock with a Yale 89 deadlocking night latch above it — that combination is what most UK insurers ask for. See the 5-lever mortice lock page for the standard and deadlocking night latch for the night latch.
How much does it cost to change a wooden door lock?
A like-for-like BS3621 5-lever mortice deadlock change starts at £180 fitted. A night latch replacement starts at £250. For a full mortice + deadlocking night latch upgrade, send photos of your current door on WhatsApp and we’ll quote an exact combined price — no call-out fee, no VAT add-on, no surprises.
Is a 5-lever mortice lock a legal requirement on wooden doors?
Not legally — but practically, yes. UK home insurance policies almost universally require either a BS3621 mortice deadlock with five or more levers, or an equivalent multi-point system, on wooden external doors. Without one, a burglary claim can be reduced or refused. The 5-lever requirement is what BS3621 itself mandates as the minimum lever count for kitemark certification. Read more on the BS3621 & insurance page.
Which mortice lock brand is best — Union, ERA or Chubb?
All three are BS3621-kitemarked and equally insurance-recognised. We rank Union 2134 first because it's the most widely stocked and ships with the cleanest hardened plates. ERA Fortress is the better-value pick. Chubb 3G114 is the premium heritage option with the heaviest case and longest service life — worth it on a Victorian or Edwardian period door.
What does BS3621 actually mean on a wooden door lock?
BS3621 is the British Standards Institute kitemark for thief-resistant locks. To carry the mark, a lock must have at least five levers, a 20mm bolt throw, hardened anti-drill plates, an anti-saw bolt insert, a minimum of 1,000 key differs, and pass a defined attack window. The kitemark is engraved on the lock faceplate — visible on the door edge when the door is open. Full breakdown on our BS3621 & insurance page.
How much should I pay to fit a BS3621 mortice lock on a wooden door?
A like-for-like BS3621 5-lever mortice deadlock change starts at £180 fitted in South London. A night latch replacement starts at £250. Both include the lock, fitting, two new keys cut on site, and a 12-month workmanship guarantee. No call-out fee. No VAT add-on. For the full combined setup, send door photos on WhatsApp for an exact combined quote.
Can I fit one of these locks myself?
You can swap a like-for-like mortice in a 44mm timber door if you have a sharp chisel, the right backset measurement and patience — but a fresh mortice cut into a heritage door without splitting the surrounding stile takes practice. For an insurance-compliant install with a kitemark certificate the insurer will accept, a fitted lock from a professional locksmith is the safer route.
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