Lock Types & Brands — Which Lock Do You Need for Your Door?

Last updated: June 2026

The wrong lock on your door doesn’t just leave you vulnerable to a break-in — it can invalidate your home insurance. Yet most homeowners don’t know what type of lock they have, whether it meets their insurer’s requirements, or whether there’s a better option available.

This guide covers every common UK door lock type, the main brands, and the honest difference between them — so you can make an informed decision rather than relying on whatever a locksmith happens to have on the van.

If you’d rather just tell us what door you have and get a recommendation: call 07486 889391 or send a WhatsApp photo of your door and lock — free advice, no obligation.

Part 1 — Lock Types: What’s On Your Door?

Euro Cylinder (uPVC, Composite & Aluminium Doors)

The most common lock type in the UK. A Euro cylinder is the oval barrel in the centre of most modern front and back doors — the part the key goes into. It operates the multipoint hooks and rollers along the door edge when the handle is lifted.

Sizes: measured as total length in mm, split either side of the central cam (e.g. 35/35, 35/45, 40/40, 45/55).

Getting the size wrong means the cylinder protrudes or recesses — both create security vulnerabilities or operational problems.

The critical vulnerability: standard Euro cylinders can be snapped with tools available in any DIY store.

The snap point is a narrowing at the centre of the cylinder — once snapped, the internal mechanism can be turned by hand in seconds. This is the most common method of forced entry on composite and uPVC doors in the UK.

What you need: a TS007 3-star anti-snap cylinder. The three stars indicate anti-snap (TS007), anti-pick (SS312 Diamond grade) and anti-bump (Sold Secure).

Most UK home insurers now specify this grade for Euro-cylinder doors.

See our anti-snap cylinder fitting service →

BS3621 5-Lever Mortice Deadlock (Timber Doors)

Set into a pocket in the body of a timber door. The key throws a solid bolt into the frame and holds it there — it cannot be pushed back without the key. The standard required by virtually every UK home insurance policy for final-exit timber doors.

“5-lever” refers to the five levers the key must align precisely to throw or withdraw the bolt. A 2-lever lock (also common on older timber doors) provides significantly less security and is non-compliant with most insurance policies.

British Standard BS3621 is the kitemark you need to see on the lock body. Without it, your insurer can refuse a claim following forced entry through that door.

What you need: if your timber front door has a 2-lever lock, a lock without a BS3621 kitemark, or no deadlock at all — it needs replacing before you can be confident your insurance is valid.

See our BS3621 mortice lock fitting service →

Rim Nightlatch (Yale-Type)

Fitted on the surface of a timber door. Latches automatically when the door is pulled closed — which is why it’s the most common cause of lockouts (key left inside, door slammed shut). Operated by a key from outside and a thumb-turn from inside.

Used alone, a rim nightlatch is not insurance-compliant for a final-exit door — it doesn’t meet BS3621. It’s intended as a secondary convenience lock alongside a mortice deadlock, not as the sole security on a front door.

Auto-deadlocking versions (which lock the latch against being pushed back when the door is closed without a key) offer significantly better security than standard spring-latch versions.

Multipoint Locking System (uPVC & Composite Doors)

The long metal strip running down the edge of a uPVC or composite door, containing multiple hooks, rollers, bolts and a central deadbolt. Operated by lifting the handle (which engages the hooks) and turning the key (which throws the deadbolt).

The multipoint mechanism is driven by the gearbox (the central case behind the handle). When the gearbox fails, nothing along the strip moves — the door appears locked but the hooks and bolts aren’t engaging. This is the most common uPVC repair job.

See our uPVC multipoint repair service →

Padlocks & Hasps (Gates, Sheds, Outbuildings)

For external use: look for a close-shackle design (where the shackle loop is exposed as little as possible, reducing attack surface), a hardened steel body, and a BS EN 12320 grade 4+ rating for insurance-compliant padlocks on outbuildings. We carry and fit heavy-duty padlocks and hasps for gates and outbuildings as part of any visit.

Part 2 — Anti-Snap Cylinder Brands Compared

This is the question we get asked most: which anti-snap cylinder should I buy?

All three brands below carry the TS007 3-star rating — they all pass the same standard test. The differences are in additional features, key restriction, and price.

Our honest recommendation:

• Budget-conscious, standard residential: Avocet ABS — excellent protection, proven track record, lowest price
• Highest pick resistance: Brisant Ultion — the Modulo pin system makes it the hardest to pick in its class
• Key control most important (landlords, commercial): Mul-T-Lock MT5+ — the restricted keyway means no unauthorised copies can be cut

All three are a significant upgrade from any standard factory-fitted cylinder. Any of them, fitted correctly, will defeat the snap attacks that account for the majority of composite and uPVC door break-ins.

Part 3 — Other Brands We Work With

Beyond the anti-snap cylinder tier, these are the brands we encounter, repair and replace across our service area:

Yale — the most recognised name in UK locksmithing. We repair and replace the full Yale range: rim nightlatches (the original Yale lock), BS3621 mortice deadlocks, high-security cylinders, and their Platinum 3-star anti-snap range. If you have Yale hardware, we carry the parts.

ERA — over 180 years in British security. ERA’s multipoint gearboxes and door mechanisms are among the most commonly fitted on UK uPVC doors, which means they’re also among the most commonly repaired. We stock ERA replacement gearboxes and mechanisms in all common sizes.

Union (formerly Chubb) — Union’s BS3621 5-lever mortice deadlocks are among the most widely fitted on UK timber doors. When a “Chubb lock” needs replacing, Union is the direct modern equivalent.

Maco, GU, Fullex, Winkhaus, Mila — the major uPVC multipoint mechanism brands fitted across UK housing stock. We stock gearboxes and replacement strips for all of these. If your door says one of these brand names on the gearbox or strip, we carry the part.

Chubb (legacy) — Chubb mortice locks are still common on older properties. We repair, service and replace Chubb mortice locks including the older warded and detector lever designs found on Victorian and period properties.

Part 4 — Which Lock Do You Need? Quick Reference

Is My Lock Insurance Compliant?

Check your home insurance policy schedule under “security requirements” or “locks.”

The most common requirements are:

• Final-exit uPVC/composite doors: TS007 3-star cylinder or kitemarked cylinder minimum
• Final-exit timber doors: BS3621 5-lever mortice deadlock
• Back and side doors: BS3621 or BS EN 12209 equivalent

If your policy says “3-star” or “TS007” and your cylinder doesn’t have three stars on its face, or if your timber door has a 2-lever or non-kitemarked mortice, you may not be covered for a claim following forced entry.

Not sure? Call us with your insurer’s name and policy reference — we’ll tell you what their standard wording requires, free of charge.

See lock replacement and upgrade service →

Areas Covered

We supply, fit and repair all lock types and brands across:

Birmingham & West Midlands — Central Birmingham, Sutton Coldfield, Solihull, Dudley, Walsall, Black Country & West

Shropshire — Telford

Home Counties — Luton · Milton Keynes · St Albans

South West — Bath, Bristol, Swindon & Gloucestershire

All areas →

Frequently Asked Questions

What is the best anti-snap lock in the UK?

All three brands we recommend — Avocet ABS, Brisant Ultion and Mul-T-Lock MT5+ — pass the TS007 3-star standard. The Ultion offers the highest pick resistance. The Mul-T-Lock MT5+ offers restricted key copying so unauthorised copies cannot be cut. The ABS is the most cost-effective.

The right choice depends on your door, budget and security priorities — call us and we’ll advise honestly.

What lock does my home insurance require?

For uPVC and composite doors: most policies require a TS007 3-star or kitemarked Euro cylinder. For timber front doors: most policies require a BS3621 5-lever mortice deadlock. Check your policy schedule under “security requirements.” Non-compliant locks can result in a reduced or refused claim after a break-in.

What size Euro cylinder do I need?

Measure the total length of your existing cylinder in millimetres — the measurement from the outside face to the cam (internal cam side). A common size is 35/35 or 35/45. If you’re not sure, send a WhatsApp photo of the cylinder removed from the door (or still in it) and we’ll confirm the size before attending.

What is a BS3621 lock?

BS3621 is the British Standard for mortice deadlocks on timber doors, requiring a minimum of 5 levers, anti-picking features, and a hardened steel bolt. It’s the standard specified by most UK home insurance policies for final-exit timber doors. The BS3621 kitemark is stamped on the lock body.

Is a Yale lock enough for a front door?

A standard Yale rim nightlatch alone is not insurance-compliant for a final-exit front door — it’s a spring latch, not a deadlock, and doesn’t meet BS3621. Used alongside a BS3621 mortice deadlock, it adds useful convenience. If your front door only has a Yale-type latch and no mortice, check your insurance policy immediately.

What’s the difference between Ultion and ABS?

Both are TS007 3-star anti-snap cylinders. The Ultion (made by Brisant) uses a 16-pin Modulo engine making it harder to pick, and has a restricted keyway meaning duplicate keys require proof of ownership. The ABS (made by Avocet) has an excellent anti-snap track record and costs slightly less.

Both are a significant upgrade from a standard cylinder.

Not Sure What You Have?

Send a WhatsApp photo of your door and lock — we’ll identify the lock type, check if it’s insurance-compliant, and give you a fixed quote for any upgrade or repair.

📞 07486 889391 — 24/7

💬 WhatsApp photo — free identification, no obligation

From £49 · No call-out fee · All major brands stocked · DBS checked