Anti-snap locks explained: TS007, Sold Secure and what your door actually needs

If you live in a house or flat with a uPVC or composite front door, there is a good chance your lock is a euro cylinder — the flat, figure-of-eight shaped barrel that the key goes into.

A cheap euro cylinder has a well-known weakness. It can be snapped. Not picked, not drilled — snapped, quickly, with ordinary tools, by someone who has watched one video.

The good news is that this is one of the cheapest genuine security upgrades available, and it is the one point in the whole locksmith conversation where paying more is clearly worth it.

What lock snapping actually is

The cylinder has a deliberate weak point in the middle, around the fixing screw. Grip the protruding end, apply force, and it breaks along that line. Remove the broken half and the mechanism inside is exposed and can be operated directly.

Two things make a door vulnerable:

• A cheap, unrated cylinder with no internal defence against snapping.
• A cylinder that sticks out past the handle. The more that protrudes, the easier it is to grip. A well-fitted cylinder should sit close to flush.

Go and look at your own front door now. If more than a few millimetres of barrel sticks out past the handle, that is worth fixing regardless of the rating.

The two ratings that mean something

TS007 — the Kitemark star rating

TS007 was created specifically in response to cylinder attacks. It uses a star rating, and the important thing to understand is that the stars can be reached in different combinations:

• 3 stars from the cylinder alone. This is what you want. The cylinder is rated to resist snapping on its own, whatever handle is on the door.
• 1-star cylinder plus a 2-star handle. This also adds up to three, and it is legitimate — but the protection now depends on that specific handle staying on that specific door.

Ask which one you are getting. If a locksmith says “3 star”, the follow-up question is “3 star cylinder on its own, or 1 plus 2?” A good one will answer immediately and without irritation.

Sold Secure Diamond

Sold Secure is an independent testing house that attacks products and rates how long they survive. Diamond is its top grade for cylinders.

The strongest cylinders carry both — TS007 3-star and Sold Secure Diamond — and many are also certified under Secured by Design, the official police security initiative for the UK.

Practical rule: ask for a cylinder that is TS007 3-star and Sold Secure Diamond. That single sentence removes almost all ambiguity from the conversation.

The other standard: BS 3621, for mortice locks

If you have a wooden front door, you probably have a mortice deadlock rather than a euro cylinder — the lock buried inside the edge of the door.

The standard here is BS 3621. It matters for a reason beyond security: many home insurance policies require a BS 3621 rated deadlock on final exit doors. A claim can be affected if the door did not meet the policy’s requirement.

Look for the British Standard Kitemark stamped on the faceplate of the lock, along with the BS 3621 number. Then read what your own policy actually says — insurers differ, and the wording is what counts, not what a locksmith tells you the wording says.

How to know you got what you paid for

This is the part people miss, and it is thirty seconds of work.

1. Ask for the packaging. Rated cylinders come in branded boxes stating the rating. If the box has gone missing, ask why.
2. Look at the cylinder itself. Rated cylinders are usually marked — a Kitemark, star markings, or the manufacturer’s name and grade.
3. Get the rating written on the invoice. Not “supply and fit new cylinder” — “supply and fit TS007 3-star / Sold Secure Diamond cylinder”. An honest locksmith will write that without being asked twice.
4. Keep the old lock. If there is ever a dispute, the parts are the evidence.

Being charged for a rated cylinder and given an unrated one is a quiet, common and hard-to-detect swap. These four steps make it very difficult.

What it should cost

A basic euro cylinder is a few pounds. A properly rated anti-snap one costs meaningfully more, and that is correct — you are buying the internal engineering that makes it survive an attack.

As a fitted job in London, expect roughly £90 to £180 in normal working hours, with the usual night premium on top. Full detail in what a London locksmith should cost, and you can sanity-check any figure you have been given with our price check tool.

If the quote is far above that, ask for the part and the labour as two separate numbers. A locksmith confident in their pricing will give you both.

Do this on a calm afternoon, not at 3am

Three things, none of which require an emergency:

• Look at your front door. How far does the cylinder stick out past the handle? Is there a Kitemark or star marking on it?
• Read your insurance policy’s lock requirement. It takes two minutes and it is the sort of thing you very much want to have read before a claim.
• If you have a basic unrated cylinder, book a replacement as a normal appointment. Daytime, booked, quoted in writing, at a fraction of the emergency rate.

A rated cylinder fitted calmly on a Tuesday costs a great deal less than the same cylinder fitted in a panic — and considerably less than a burglary.

Standards and bodies referenced

• Sold Secure — independent attack testing and grading
• Secured by Design — the official police security initiative
• Master Locksmiths Association — vetted and inspected members

We do not name lock brands or link to retailers, and we take no payment from anyone. Ask for the rating; let the locksmith pick the brand that meets it.

Checked 27 August 2026.