The quick answer

Most uPVC and composite doors lock with a euro cylinder — the round barrel the key goes into. It's the most common way in for a break-in, because it can be snapped in two with a wrench in seconds. The fix is a TS007 3-star cylinder, a straight ten-minute swap on your existing door.

Check your own door in 30 seconds

  • Look at the cylinder on the edge of the door, where the key goes in.
  • Check how far it sticks out past the handle plate around it.
  • More than about 3mm proud and there's enough to grip with a wrench or pliers — that's the vulnerable case.
  • Flush, or close to it — you're already in better shape.

Not sure what you're looking at? Send me a photo and I'll tell you straight, no callout needed for that.

What TS007 means

It's the British test standard for euro cylinders. Every tested cylinder gets a star rating on the box:

RatingWhat it means
1 starBasic snap resistance on the cylinder alone
2 starExtra protection built into the door handle, not the cylinder
3 starThe cylinder resists snapping on its own — the one to look for

A 1-star cylinder paired with 2-star handles gets you to the same place, but a genuine 3-star cylinder does the whole job on its own — that's what I fit. It's this Kitemark that insurers are checking for, not a brand name. The rating covers more than snapping, too: drilling, picking and bumping are all part of the same test.

Does your insurance actually require it?

Check your own policy wording rather than take anyone's word for it, mine included — but it's common for UK home insurance to reference door security standards, and a cylinder with no snap resistance can complicate things if you ever need to claim after a break-in. A 3-star Kitemark is the straightforward way to answer that question before it comes up, not after.

What the fitting actually involves

  1. The old cylinder comes out — one screw on the edge of the door releases it, and it slides out of the handle.
  2. It gets measured properly. A euro cylinder is sized in two halves either side of the door thickness — get this wrong and the new one either doesn't turn cleanly or sticks out just as far as the old one did, which defeats the point.
  3. The new 3-star cylinder goes in, and I test the key turns smoothly from both sides — inside and out — before I call it done.

Ten minutes, start to finish, and it's the same £70–£90 lock change price as any other cylinder swap.

"Prompt, professional and tidy. Fitted my new lock quickly, works perfectly. Fair price and highly recommended."

Raheem A, Nottingham

The cylinder I fit on my own door

A genuine TS007 3-star anti-snap cylinder is what's on my own front door, and it's what I fit for anyone who asks — not the cheapest on the supplier's list, not the most expensive, just the one that does the job it's rated for.

It's a ten-minute job, so it's worth doing before you need it rather than after a break-in. I fit them across Beeston, Bulwell, Arnold, West Bridgford, Hucknall, Ilkeston and Derby — send a photo of your cylinder first if you're not sure what you've got.

FAQ

What is lock snapping?
Snapping the euro cylinder in two with a wrench, in seconds. It's the most common way into a uPVC or composite door in the UK.
How do I know if my door is at risk?
Check the cylinder — if it sticks out more than about 3mm past the handle plate, there's enough to grip with a tool. Thirty seconds, no locksmith needed.
What does TS007 mean?
The British test standard for euro cylinders, rated 1 to 3 stars. A 3-star cylinder resists snapping on its own — the number to look for.
Does upgrading damage my door?
No — it's a cylinder swap, not a new lock. The mechanism inside the door doesn't change, and your existing keys usually still work with a new cylinder cut to match.
What does it cost?
It's a standard lock change on my price list — £70–£90 fitted, fixed and quoted before I start. No separate call-out, no upsell once I'm there.
Does my home insurance require this?
Check your policy wording, but many insurers ask about door security standards, and a cylinder with no snap resistance can complicate a claim after a break-in. A 3-star Kitemark is the easiest way to answer that question with a yes.
Does a 3-star cylinder also stop picking and bumping?
Yes — TS007 3-star testing covers snapping, drilling, picking and bumping, not just snapping alone. It's the most complete rating a single cylinder can carry.