Insurer-Compliant · BS3621 · TS007 3-Star

Insurance-Approved Door Locksin South London

Policy schedule say BS3621 or equivalent? We fit the exact Kitemark lock your insurer wants — mortice, cylinder, multi-point — and leave you with a signed compliance invoice to keep on file. Across Croydon, Sutton, Bromley, Lambeth and every SE/SW/CR/SM postcode.

BS3621 Kitemark stock fitted TS007 3-star anti-snap cylinders BS8621 for flats & HMOs Free compliance certificate DBS-checked · fully insured 30-minute South London response
Google Rated 5.0 BS3621 Stock Fitted DBS Checked 30-Min Response Free Compliance Certificate No Call-Out Fee
Fitting compliant BS3621 locks since 2015 Aviva, Direct Line, Admiral, AXA, Churchill, LV — we speak your policy TS007 3-star · Sold Secure Diamond · PAS 24 · BS8621 Same-day fit across SW/SE/CR/SM/BR postcodes Free compliance audit with every job Fitting compliant BS3621 locks since 2015 Aviva, Direct Line, Admiral, AXA, Churchill, LV — we speak your policy TS007 3-star · Sold Secure Diamond · PAS 24 · BS8621 Same-day fit across SW/SE/CR/SM/BR postcodes Free compliance audit with every job

What "Insurance Approved" Actually Means

Your insurer doesn't care how expensive your lock looks. They care about one Kitemark stamped on the faceplate.

Every major UK home insurer — Aviva, Direct Line, Admiral, Churchill, LV, AXA, Hiscox — writes a lock clause into your policy schedule. That clause almost always says "BS3621 or equivalent" for final-exit timber doors, "multi-point locking with a TS007 3-star or Sold Secure Diamond cylinder" for uPVC and composite, and "key-operated locks on all accessible windows". If the lock you fitted after a break-in doesn't match that exact wording, the insurer can — and often will — reduce or refuse the claim. We see it every month.

An insurance-approved door lock is a lock assembly that carries a recognised UK security standard stamped or engraved on the metal itself. The Kitemark oval is the one insurers look for. On a 5-lever mortice deadlock you'll find it etched on the faceplate next to "BS3621". On a euro cylinder you'll find it on the cap: one star (picking, drilling, bumping resistance) or three stars (adds snap-resistance). Without that mark, you can have a £400 lock from a high-street brand that still fails your policy wording.

This page is the long answer. We explain every standard that matters in 2026, what your insurer actually requires for timber vs uPVC vs composite vs flats, what happens to your claim if the locks are wrong, and which brands we routinely fit across every South London postcode. If you'd rather skip the reading, WhatsApp a photo of your lock and we'll tell you in two minutes whether it passes. If you want the reasoning behind our recommendations, keep reading — our team has been fitting Kitemark locks across SW, SE, CR, SM and BR postcodes since 2015 and every fit comes with a signed compliance invoice you can file with your insurer. Questions? The contact page has our direct numbers, and our Locksmith Advice blog goes deeper on specific standards if you need the technical detail.

Quick referenceBS3621 = 5-lever mortice, key egress both sides, timber doors. BS8621 = same security, thumbturn inside, flats and HMOs. TS007 3-star = snap-resistant euro cylinder, uPVC and composite. Sold Secure SS312 Diamond = the highest independent cylinder rating. If your locks don't have at least one of these stamps, your policy probably doesn't cover you.

What Your Policy Actually Says

Insurer Policy Wording — Decoded Side by Side

Every guide tells you to "check your policy". Nobody shows you what six of the biggest UK insurers actually write. Here are the real clauses, pulled from 2026 policy wording documents, and the Kitemark stamp that satisfies each one.

Insurer
What the policy says (lock clause)
Stamp required
Aviva
Wooden doors must have a five-lever mortice deadlock, a cylinder rim deadlatch with key-locking internal handle, or any lock approved to BS3621. PVCu doors require a multi-point locking system. All accessible windows must have key-operated locks.
BS3621 Kitemark
Direct Line
Final exit doors must be fitted with a mortice deadlock that conforms to British Standard 3621, or a key-operated multi-point locking system for PVCu doors. All accessible windows fitted with working key-operated locks.
BS3621 or
MPL + TS007
Admiral
BS3621 offers the maximum security for wooden doors. Fit a mortice deadlock or key-operated bolt on all other external doors. Fit key-operated locks on all accessible windows, including any above a flat roof or balcony.
BS3621
Churchill
All final exit doors must be secured by a mortice deadlock to BS3621 (or equivalent) or a multi-point locking system. Key-operated window locks must be engaged on all accessible opening windows whenever the property is unoccupied.
BS3621 equivalent
LV=
We require your home to be fitted with locks approved to British Standard 3621 on all external doors — or a multi-point locking system with a TS007 3-star rated cylinder on PVCu and composite doors.
TS007 3-Star
for uPVC
Hiscox
Whenever the home is left unoccupied, all external doors must be fitted and locked with the locks shown in your schedule. Final exit doors must meet the lock standard specified in your schedule (typically BS3621 or BS8621 for flats).
Schedule-specific

Policy wording paraphrased from 2026 documents. Your personal schedule overrides general wording — send us a photo of your lock clause and we'll tell you exactly which Kitemark you need.

Kitemark Codes You Actually Need

Six Standards, Decoded — Know Exactly Which Stamp Your Door Requires

UK lock standards sound like alphabet soup. Here's what each one actually means, which door it applies to, and why your insurer cares about the difference between BS3621 and BS8621 — a distinction that's cost London leaseholders five-figure claim refusals.

BS3621:2007+A2

BS3621 Mortice

Timber Final-Exit Doors

The default insurance standard for wooden front and back doors. Key-operated both sides, minimum 5 levers (or equivalent cylinder), 20mm bolt throw, and proven to resist 5 minutes of drilling and picking attack.

  • Kitemark engraved on faceplate
  • Mentioned by name in Aviva, Direct Line, Admiral, LV policies
  • Not suitable for flats under fire regs
Fit where: timber front/back doors, outbuildings, garages with habitable space aboveFrom £180 supplied & fitted
BS8621:2007+A2

BS8621 Keyless Egress

Flats · HMO · Fire-Escape Doors

Same thief-resistance spec as BS3621 but with a thumbturn inside — meaning no key needed to exit in an emergency. Mandatory for flats and HMOs under the Regulatory Reform (Fire Safety) Order 2005.

  • Keyless escape from inside (fire-safe)
  • Required on final-exit doors of flats
  • Dual BS3621/BS8621 locks exist for landlords
Fit where: flats, HMOs, short-lets, any door legally requiring keyless escapeFrom £180 supplied & fitted
BS10621

BS10621 Restricted Egress

Commercial · Shops · Warehouses

Identical thief-resistance to BS8621 but with a controlled thumbturn that can be key-overridden externally. Used on commercial premises that need to "dead-lock" during closed hours while allowing keyless escape while occupied.

  • Hybrid keyless/key-override
  • Retail, offices, small warehouses
  • Accepted on many commercial insurance policies
Fit where: shops, offices, commercial premises with closing hoursFrom £200 supplied & fitted
TS007 KITEMARK

TS007 1-Star & 3-Star

Euro Cylinders · uPVC · Composite

The critical anti-snap standard. 3-star cylinders have a sacrificial break section engineered to snap at a point that leaves the lock mechanism intact — defeating the 10-second snap attack. A 1-star cylinder must be paired with a 2-star handle to total 3-star protection.

  • 1-star: picking/drilling/bumping resistance only
  • 3-star: adds snap-resistance (sacrificial break)
  • Stamped on cylinder cap with star icons
Fit where: uPVC doors, composite doors, aluminium doorsFrom £200 supplied & fitted
SOLD SECURE SS312

SS312 Diamond Grade

Premium Anti-Snap Cylinder

The highest independent cylinder rating in the UK. Tested against drilling, picking, bumping, and snap-resistance over 5 minutes of sustained attack. Brands at this grade: Avocet ABS, Ultion Plus, Mul-T-Lock MT5+.

  • Diamond (highest) / Gold / Silver / Bronze
  • Diamond exceeds TS007 3-star in most tests
  • Accepted by every UK insurer we've seen
Fit where: any uPVC/composite door, ideal for high-target South London areasFrom £220 supplied & fitted
PAS 24:2022

PAS 24 Doorset

Whole-Door Enhanced Security

Unlike the others, PAS 24 certifies the entire doorset — door, frame, locks, hinges, glazing — against manual attack, soft and hard impact. Required under Building Regulations Part Q for new-build homes. Pairs with TS007 3-star cylinders.

  • Whole-door certification (not just lock)
  • Mandatory on new-build under Part Q
  • Core standard of Secured by Design scheme
Fit where: new composite doors, replacement external doors, Secured by Design retrofitsSpecification quote only

Door-Type Compliance Matrix

Your Door Decides the Standard — Not the Other Way Round

Fit a BS3621 mortice to a uPVC door and you've wasted £180 — the insurer will still reject the claim. Match the Kitemark to the door material, not the other way round.

Timber Front Door

Wooden · Single-leaf · Key both sides

Required

BS3621 5-lever mortice deadlock fitted centrally at waist height, plus a BS Kitemarked nightlatch (BS EN 12209) as a secondary latch for day use.

A 3-lever mortice or a single nightlatch alone is not insurance compliant — even if the lock is brand new.

uPVC Door

Multi-point · Hooks & bolts · Handle-lift

Required

Working multi-point locking system plus a TS007 3-star euro cylinder (or 1-star cylinder + 2-star handle = 3-star total). Sold Secure Diamond cylinders are accepted equivalently.

Any euro cylinder without TS007 or SS312 marking fails the snap test — this is the #1 South London burglary entry method.

Composite Door

GRP/timber core · Multi-point · PAS 24

Required

Multi-point lock + TS007 3-star cylinder is the minimum. If the door came from a Secured by Design specifier it should already carry PAS 24 — retain that cert for your insurer.

Budget "6-hook" composite doors often ship with 1-star cylinders. Upgrade day one — the door is strong, the cylinder isn't.

Patio / French Doors

Double-leaf · Sliding or hinged

Required

Key-operated locks on both leaves — typically a multi-point on the active leaf plus a shoot-bolt or flush-bolt on the passive leaf. Anti-lift bolts fitted on sliding tracks.

Sliding patio doors with only a handle latch fail every major UK policy. Fit a dedicated patio lock with an anti-lift hook.

Flat / HMO Front Door

Communal block · Fire escape route

Required

BS8621 keyless-egress mortice. BS3621 is not acceptable — it requires a key to exit, which violates fire safety law. Dual BS3621/BS8621 locks satisfy both insurance and fire regs.

Landlords: fitting BS3621 on an HMO door can trigger a fire-safety prohibition notice with fines up to £5,000 per door.

Garage / Side Door

Secondary access · Often overlooked

Required

Same standard as the front door if the garage connects to the house (integral garage). A BS3621 mortice or a multi-point with a TS007 3-star cylinder — your insurer treats this exactly like the front door.

80% of integral garage doors we inspect across South London fail insurance — it's the most-overlooked weak point in the policy.

Brands We Routinely Stock & Fit

Insurance-Approved Lock Brands That Actually Pass the Test

Not every branded lock is insurance compliant — even some £400 designer options fail the BS3621 or TS007 test. These are the exact brands and specific models we supply from our South London van, every one certified to a standard your insurer will accept.

UL
TS007 3-Star

Ultion Plus

Sold Secure Diamond

Hidden 11th pin, Diamond-rated, £1,000 guarantee on forced entry. The go-to replacement cylinder for uPVC and composite doors across South London.

YL
TS007 3-Star

Yale Platinum

3-Star Anti-Snap

Kitemarked 3-star cylinder with £1,000 guarantee. A popular choice across uPVC retrofits — widely recognised, every insurer accepts it.

MT
SS312 Diamond

Mul-T-Lock MT5+

Restricted Keyway

Key duplication controlled by card. Diamond-rated, pick-resistant pin-in-pin mechanism. Ideal for HNW and HMO landlords.

ER
BS3621

ERA Fortress

5-Lever Mortice

BS3621 Kitemark 5-lever mortice deadlock. Our default mortice upgrade for timber front doors — robust, well-priced, insurer-recognised.

CH
BS3621

Chubb 3G114E

Premium 5-Lever

The heritage choice for Victorian and Edwardian South London front doors. BS3621 certified with hardened steel bolt and forged levers.

UN
BS3621

Union 2134E

StrongBOLT 5-Lever

Budget-friendly BS3621 that doesn't compromise on standard. A common spec for landlords upgrading tenant front doors across SE postcodes.

AB
SS312 Diamond

ABUS Bravus 4000

German Engineering

Magnetic pin system, registered key card, Sold Secure Diamond. A serious upgrade for doors in higher-risk postcodes or repeat-target properties.

Not sure which brand fits your door? Most uPVC doors accept any of the 3-star cylinders above — the fit is standardised on Euro profile sizing (35/10/30, 40/10/35, etc). Timber door mortice pockets vary: 2.5" or 3" is the common size. WhatsApp a photo of the lock edge and we'll spec the exact brand and keyway for your door before we arrive.

The 60-Second Lock Audit

Six Questions That Tell You If Your Locks Pass — Before We Even Arrive

We do this audit with every customer on the phone before dispatch. It takes one minute and tells us exactly what you need so we can bring the right parts on the first visit.

Walk to your front door, your back door, and any patio or garage door. Look at the lock edge — the thin strip of metal visible when the door is open. That's where the Kitemark is engraved. Then run through these six questions.

If you answer "no" or "not sure" to any three of these, your door almost certainly fails at least one major insurer's policy schedule. Call us on 020 8050 2017 and we'll fix every gap on a single visit.
  1. Is there a Kitemark oval stamped on the faceplate?

    Look for the oval BS Kitemark next to "BS3621" on timber mortice locks, or stars (1-star / 3-star) on cylinder caps. No mark = no compliance.

  2. Does your front door have a deadlock — not just a nightlatch?

    A nightlatch alone (the spring latch above the handle) is not insurance compliant. You need a deadlock fitted below it. Two locks = minimum spec.

  3. On a uPVC door, does the cylinder show three stars?

    Pull the key out. Look at the cap of the cylinder where the key goes in. Count the stars. Three stars = snap-proof. One star or none = replace today.

  4. Do your windows have key-operated locks engaged at night?

    Every ground-floor and accessible first-floor window must have a key-operated lock, and your policy requires them to be locked when you're out. Working handle locks do not count.

  5. If you're in a flat, can you exit without a key?

    Feel the inside of the lock. Thumbturn = BS8621 compliant + fire safe. Keyhole only = BS3621 = fire safety violation. Flats must have keyless egress by law.

  6. Do you have a written invoice proving a Kitemark lock was fitted?

    If your claim is disputed, a locksmith's invoice stating "BS3621 Kitemark supplied and fitted" is often the strongest piece of evidence. We give you one as standard.

If The Worst Happens — What Your Insurer Does Next

The Claim-Rejection Pipeline: Why £180 of Lock Can Save a £30,000 Claim

When a burglary claim reaches a loss adjuster, this is the exact sequence they follow. Every stage is a chance for the insurer to close the claim as non-compliant. Understanding the pipeline is the reason you fit the right locks now, not after.

01

Forced-Entry Evidence

Adjuster photographs the attacked lock and frame. No damage = no forced entry = claim rejected before lock spec is even checked.

02

Lock Standard Check

They look for a Kitemark stamp on the faceplate or cylinder cap. No mark is treated as non-compliant by default unless you can prove otherwise.

03

Policy Schedule Cross-Check

Your schedule text is matched to the actual lock. "BS3621 or equivalent" on your policy plus a 3-lever mortice on your door equals refusal.

04

Claim Decision

Insurer issues a Statement of Claim — most commonly a full rejection, sometimes a reduction of up to 100% of the theft element. Only the building damage is paid.

Your Best Defence

A signed invoice stating "BS3621 Kitemark supplied and fitted" holds up in every insurance dispute we've seen.

We issue one as standard after every compliance job. It lists the door location, lock standard, cylinder rating (where applicable), and the engineer's name. Keep it with your policy paperwork. If your claim is ever disputed, that single sheet of paper is your strongest piece of evidence.

Book a Compliance Visit →

Landlords, HMOs & Flats — Three Separate Legal Regimes

If You Rent Out Property, Your Lock Standard Isn't Just About Insurance

Private landlords, HMO operators and flat leaseholders each face a different legal duty on door locks. Fit the wrong lock and you're not only uninsured — you can be fined under fire safety law, served with a prohibition notice, or held personally liable for a tenant injury.

Private Landlord

Single Residential Let

Your landlord insurance typically requires BS3621 on timber external doors and a multi-point + TS007 3-star on uPVC. Different from owner-occupied policies — expect stricter window-lock language too.

  • BS3621 or TS007 3-star on every external door
  • Key-operated locks on all accessible windows
  • New keys issued to every new tenancy
  • Lock compliance invoice kept with tenancy file
A non-compliant lock can void both the theft and the liability portions of the policy if a claim involves forced entry.
Fire Safety Order 2005

HMO & Multi-Let Property

Any HMO (three or more unrelated tenants in shared facilities) is governed by the Regulatory Reform (Fire Safety) Order 2005. Final-exit doors must allow keyless escape. BS3621 is non-compliant.

  • BS8621 on all final-exit and communal doors
  • Thumbturn inside, key lockable outside
  • Certificate of compliance on file for inspection
  • Dual-certified BS3621/BS8621 locks available
Fines of up to £5,000 per door and prohibition notices under RRFSO Article 32 — London Fire Brigade enforces actively.
Leaseholder · Flat

Flat Owner-Occupier

If you own a flat, your buildings insurance is usually block-level (arranged by the freeholder) but your contents policy is yours. The contents insurer will ask about your front-door lock standard and your policy schedule binds you.

  • BS8621 (not BS3621) on the flat front door
  • Check the block's fire risk assessment
  • Don't fit a deadlock that blocks keyless escape
  • Notify freeholder of any lock change
A BS3621 fit to a flat door can void your contents policy AND breach the block's fire safety case — double exposure.

Our Insurance Lock Services

Every Compliance Job, Fitted the Same Day

One van, all the Kitemarks. Every service below is a fixed-price, same-day visit across South London — and every job ends with a signed compliance invoice for your insurer.

BS3621 Mortice Upgrade

3-lever or unmarked mortice swapped for a full Kitemarked BS3621 5-lever deadlock. Takes about 45 minutes on a standard timber door.

from £180

TS007 3-Star Cylinder

Snap-proof cylinder fitted to any Euro-profile uPVC or composite door. Multi-brand: Ultion, Avocet, Yale Platinum, Mul-T-Lock.

from £200

Euro Cylinder Replacement

Standard cylinder swap for insurance compliance. Correct size measured on site. Kitemark engraved on every cylinder we stock.

from £135

Full uPVC Gearbox

Multi-point locking strip replacement — hooks, bolts, centre case. When a uPVC door no longer locks at the handle-lift stage.

from £350

Free Compliance Audit

Every external door, every window lock, photographed and checked against your insurer's schedule. Written report emailed the same day.

Free with any job

BS8621 for Flats & HMOs

Fire-safe keyless-egress mortice. Dual BS3621/BS8621 locks available for landlords needing insurance + fire code compliance on one lock.

from £180

Window Lock Compliance

Key-operated locks fitted to all accessible windows — ground floor, above flat roofs, and anywhere an insurer can argue an accessible gap.

from £180

Post-Break-In Compliance

After a forced entry, your insurer expects like-for-like or better replacement. We fit to the exact schedule spec and document everything photographically for the claim.

from £135

Fixed-Price Insurance Compliance

Transparent Pricing — No VAT, No Call-Out, No Surprises

These are the real rates we quote on the phone. Prices pulled from our 2026 schedule — unchanged since you called, and backed up in writing on the invoice.

Euro Cylinder Change

Standard insurance-compliant cylinder on a uPVC or composite door

from£135
  • Correct size measured on site
  • Kitemark-engraved cylinder fitted
  • New keys issued and tested
  • Compliance invoice included
Book Now

TS007 3-Star Upgrade

Snap-proof, anti-pick, anti-drill upgrade for any Euro-profile door

from£200
  • Ultion, Avocet, Yale or MTL brand
  • 3-star or Diamond rated
  • Warranty on cylinder register
  • Old cylinder removed & disposed
Book Now

Full uPVC Gearbox

Complete multi-point strip-out when the door won't lock at handle-lift

from£350
  • Hooks, bolts, centre case replaced
  • Handle alignment corrected
  • New cylinder where needed
  • Door re-tested for throw
Book Now
No VAT added No call-out fee — ever Fixed prices agreed before we start 12-month workmanship guarantee

How It Works

Three Steps. Same Day. Done Before Teatime.

No surveys, no quotes that take a week, no returning three times for different parts. One visit, full compliance.

01

Call or WhatsApp a Photo

Send us a photo of the lock edge and your policy schedule. We'll tell you within 10 minutes exactly which Kitemark you need — and quote a fixed price over the phone.

02

We Arrive With The Right Lock

Van stocked with every BS3621 mortice size, every TS007 3-star cylinder and every BS8621 option. Typical response: 30 minutes across South London.

03

Fitted · Tested · Documented

Lock fitted, tested, photographed. You get a signed compliance invoice emailed within an hour — ready for your insurer's file. Job done.

Why Choose Locksmith South London

Fitting Kitemark Locks Across South London Since 2015

We're the team South London landlords, estate agents and post-break-in homeowners call when the lock has to pass an insurer's schedule — not just look good. Every van is stocked with BS3621, BS8621, TS007 and Sold Secure Diamond options. Every job ends with a compliance invoice you can file.

See the locations we cover, read our locksmith advice blog, or meet the team. When you're ready, the contact page has every direct number and email we use.

10+ YrsInsurance-compliant lock fitting across SW, SE, CR, SM, BR postcodes
5.0 ★Google rating from verified South London customers
30 MinTypical response time across central South London
2,400+BS3621 and TS007 locks fitted in the last 5 years

DBS Checked

Every engineer cleared for tenanted and landlord work

Fully Insured

Public liability + professional indemnity cover in place

BS3621 Stock Fitted

Every van carries 3 sizes of mortice + 10 cylinder variants

Free Compliance Audit

Photo-documented check of every door and window on request

Phone Quote In 10 Min

Flat-rate pricing agreed before we dispatch the van

30-Minute Response

Van already in your postcode most of the working day

Compliance Invoice

Emailed the same hour — ready for insurer's claim file

12-Month Guarantee

Workmanship warranty plus full manufacturer lock cover

What South London Homeowners Say

5.0 Stars, Signed Compliance Invoices, Real Post-Break-In Claims

Reviews pulled from Google and verified customer WhatsApp feedback — we've kept names to first name + last initial as they came through.

Had a break-in at our flat in Streatham. Our LV policy said BS8621 — I had no idea what that was. The team arrived within 40 minutes, fitted a dual-certified lock, and emailed me a compliance invoice before they left the drive. The insurer paid the full claim three weeks later without a single dispute.

NA

Nadia A.

Streatham · SW16

Verified

I manage 14 HMO units in Croydon and Thornton Heath. Previous locksmith fitted BS3621 everywhere — Fire Brigade turned up, found keyed egress on two buildings, threatened prohibition. This team came out, swapped 26 locks to BS8621 in three days, and documented every one. No more sleepless nights about fire enforcement.

KO

Kemi O.

Croydon · CR0

Verified

Moved into a new uPVC composite door in Bromley. Admiral insurance asked me for a TS007 cert. I called around — three places wanted to survey first and quote next week. This team told me on the phone the cylinder was only 1-star, brought an Avocet ABS Diamond the same afternoon, fitted it in 25 minutes. Admiral accepted the invoice over email.

TB

Theo B.

Bromley · BR1

Verified
Insurance approved front door with mortice deadlock South London

Free with every lock upgrade

A written compliance invoice — the one piece of paper insurers actually want.

Emailed to you within an hour of the fit, listing the door, the standard, the Kitemark number, and the engineer who did the work. Keep it with your policy. If your claim is ever disputed, this is the document that settles it.

Your Questions, Answered

Insurance-Approved Door Lock FAQs

The questions we answer most often on the phone — taken straight from UK homeowner search data.

What locks do I need for home insurance in the UK?

Most UK home insurers require a BS3621 5-lever mortice deadlock on final-exit timber doors, a TS007 3-star or Sold Secure SS312 Diamond euro cylinder on uPVC and composite doors, and key-operated locks on all accessible windows. Aviva, Direct Line, Admiral, Churchill, LV= and AXA all reference BS3621 or equivalent language in their policy schedules. If you live in a flat or HMO, BS3621 is replaced by BS8621 to satisfy fire-safety keyless-egress rules.

How do I check if my door locks are insurance approved?

Open the door and look at the lock edge — the metal faceplate visible on the door's edge when open. On a mortice deadlock, the Kitemark oval with "BS3621" is engraved on the faceplate. On a euro cylinder, look at the cap where the key goes in: one star or three stars indicates TS007 rating. If you see no mark, it's almost certainly not compliant. Use our 60-second audit checklist above, or WhatsApp a photo and we'll confirm within 10 minutes.

Will my claim be rejected if my locks aren't BS3621?

Yes — if your policy schedule specifies "BS3621 or equivalent" and your claim involves a forced-entry burglary, the insurer is entitled to reduce or refuse the theft element of the claim when the locks don't meet that standard. We see this happen most often with homeowners who inherited 3-lever mortice locks from the previous owner without checking. Fitting compliant locks and keeping the locksmith's invoice on file is the strongest defence. It's not hypothetical — the Financial Ombudsman Service publishes regular decisions backing insurers on this.

What lock does my uPVC door need for insurance?

A uPVC or composite door needs a multi-point locking system plus a TS007 3-star euro cylinder, or a 1-star cylinder paired with a TS007 2-star security handle. The 3-star cylinder is engineered to snap at a sacrificial break point instead of failing open — defeating the lock-snapping attack that causes most South London uPVC break-ins. Sold Secure Diamond (SS312) is accepted as equivalent by every major UK insurer.

Do flats and HMOs need BS3621 or BS8621?

Flats and HMO final-exit doors need BS8621, not BS3621. BS8621 has the same thief-resistance specification but allows keyless escape from the inside via a thumbturn — a fire-safety requirement under the Regulatory Reform (Fire Safety) Order 2005. Dual-certified BS3621/BS8621 locks are available and satisfy both insurance and fire law at the same time. Fitting the wrong standard on an HMO can trigger fines up to £5,000 per door.

How much does an insurance-approved lock cost in South London?

A BS3621 5-lever mortice replacement is from £180 supplied and fitted. A TS007 3-star anti-snap cylinder upgrade is from £200. A full multi-point gearbox strip-out on a uPVC door is from £350 (or £450 for a complete rebuild). Every price is fixed before the van leaves, with no VAT, no call-out fee, and a 12-month workmanship guarantee. See our pricing table above for the full fixed-price list.

What's the difference between TS007 1-star and 3-star?

TS007 1-star cylinders are tested against picking, drilling and bumping — but not cylinder snapping. They must be paired with a TS007 2-star security handle that covers the cylinder protrusion to achieve 3-star total protection. A TS007 3-star cylinder (or Sold Secure Diamond SS312) resists all five attacks including snap attack, thanks to a sacrificial break section engineered into the cylinder body. Most insurers accept either combination provided the total door rating reaches 3-star.

Do my windows need key-operated locks too?

Yes. Every major UK insurer specifies key-operated locks on all accessible windows — ground floor, windows above flat roofs or balconies, and basement windows. Handle-operated locks with no key are not insurance compliant because they can be slipped through broken glass. Window lock fitting is from £180 across South London and can be done on the same visit as your door compliance upgrade.

Does fitting BS3621 locks lower my insurance premium?

Some insurers offer a small discount (typically 2-5%) for homes fitted with BS3621 and TS007 3-star locks across all external openings. The bigger benefit isn't the premium — it's claim certainty. You're paying the same premium either way, but compliant locks mean the insurer can't reduce or refuse a theft claim on a technicality. Most homeowners save far more on one successful claim than they'd ever save on premium discounts.

Related Locks & Areas We Cover

Keep Reading — or Find Your Postcode

Every link below resolves to a live page on this site. Browse related lock standards, explore the site, or find the South London area closest to you.

Don't let a £180 lock cost you a £30,000 claim

Book a Compliance Visit — Fitted the Same Day

Call now for a fixed-price quote, or WhatsApp a photo of your lock and your policy schedule. We'll tell you in ten minutes exactly which Kitemark you need — and the van is probably already on your postcode.

30-minute response Fixed phone quote Free compliance invoice No VAT · No call-out fee