In short: most UK home insurance policies name the lock standard your final exit doors must have, usually BS 3621 on a timber door and a multipoint lock with a rated cylinder (TS 007 3-star or equivalent) on uPVC and composite doors. Hardly anyone reads that page of the policy until after a break-in. Check yours in five minutes, and if it names a standard your door doesn’t meet, put it right before you need to claim.
Let me be straight with you about what you’re reading. I’m a locksmith, not an insurance broker and not a lawyer. What follows is what I’ve learned fitting locks across Hythe, Totton, Marchwood and Southampton, and what customers have told me after a claim went sideways. Your policy is the only document that counts, so read it alongside this.
The short version:
- Most policies carry a “minimum security” condition that names a lock standard for the doors you leave the house by.
- Back doors, side doors and patio doors count as final exit doors too.
- The standard is usually BS 3621 on timber doors and a rated cylinder on uPVC and composite doors.
- There’s no such thing as an “insurance approved lock”. There are locks that meet the standard your policy names.
- I fit BS 3621 and TS 007 3-star locks every week. Prices are on the price list, and a free home security check tells you where your doors stand.
What does my policy actually require?
Somewhere in the policy wording, often under “Conditions” or “Minimum security requirements”, there’s a paragraph most people have never read. The usual shape of it is this: the final exit doors must be fitted with either a five-lever mortice deadlock to BS 3621, or a multipoint locking system with a key-operated cylinder, and accessible windows must have key-operated locks. Some insurers only apply the condition once you’ve told them you have those locks (because it earned you a discount). Others apply it to everyone. Some say nothing at all. That’s why the first job is to read yours, not mine.
The words to search for in the PDF are “BS 3621”, “British Standard”, “minimum security”, “final exit” and “key-operated”. If none of them appear, your policy probably has no lock condition and this page is just good advice. If they do appear, keep reading.
What do BS 3621 and TS 007 mean in plain English?
BS 3621 is the British Standard for a thief-resistant lock that needs a key on both sides. On a timber door that’s the five-lever mortice deadlock, and a proper one carries the Kitemark and the number stamped on the faceplate. There are two close relatives: BS 8621, which unlocks from inside without a key (a thumbturn, for flats and rented homes where fire escape matters), and BS 10621, which opens from inside without a key day to day but can be deadlocked from outside with the key when the house is empty. Insurers generally treat all three the same. I wrote up the whole family in BS 3621 explained in plain English.
TS 007 is the standard for the cylinder in a uPVC or composite door, the barrel your key goes into. It’s rated in stars. A 3-star cylinder has passed the snap, drill, pick and bump tests on its own. A 1-star cylinder behind a 2-star security handle adds up to the same three stars. A plain, unrated cylinder is what most doors were built with, and it’s what lock snapping was invented for. Sold Secure Diamond is a different test house’s mark for the same job; insurers who ask for a rated cylinder usually accept either.
What I fit as standard on a uPVC lock change is a 6-pin anti-pick, anti-drill cylinder. The TS 007 3-star anti-snap upgrade is a paid option, from £150 fitted, and it’s the one I’d want on my own front door.
Can an insurer really turn down a claim over a lock?
Yes, in the right circumstances, and no, not as freely as some people will tell you. Here’s the honest picture as I understand it.
If your policy has a lock condition, you told the insurer you met it, and a burglar got in through a door that didn’t, you’ve got a problem. The insurer can argue the condition wasn’t kept and reduce or refuse the claim. That’s the case I hear about most, and it’s the one this page exists to stop.
What the law changed in 2015 is the other end of it. Under the Insurance Act 2015, an insurer generally can’t rely on a security condition to refuse a loss that the condition couldn’t have affected. If your kitchen catches fire, the lock on the back door isn’t the reason, and it shouldn’t be the reason a fire claim fails. I’ve read older advice, including a version of this page, that said a claim can be refused “even if there’s no connection” between the lock and how the burglar got in. That’s stronger than the law, and I’d rather you had the accurate version. It’s for you to show the breach couldn’t have made that loss more likely, so keep it in mind rather than banking on it. I’m not a lawyer; if a claim of yours is being questioned, complain to the insurer first, and if you’re not satisfied the Financial Ombudsman Service is free to use.
The practical rule is simpler than the legal one. If the policy names a standard, meet it. Then there’s nothing to argue about.
How do I check my own doors in five minutes?
- Timber front or back door: open it and look at the edge. A BS 3621 mortice lock has the Kitemark and “BS 3621” on the metal faceplate. A Yale-type night latch on its own doesn’t meet it, however good the latch is.
- uPVC or composite door: look at the cylinder where the key goes in. A rated one carries the Kitemark and stars, or the Sold Secure diamond, on the face. If the face is blank, it’s almost certainly unrated. Separately, if it sticks out more than about 3mm past the handle, it’s an easy snap whatever it’s rated.
- Patio and French doors: the same test. If they lock with a key, check what they lock with. If they lock with a handle only, they don’t meet a key-operated condition.
- Windows on the ground floor and any easy climb: key-operated handles or locks, and the keys somewhere sensible, not left in.
- Still not sure? WhatsApp me a photo of the door edge and the cylinder on 07453 327708 and I’ll tell you what you’ve got. Or I’ll come and look for free.
What does putting it right actually cost?
Less than people fear, and less than the excess on a burglary claim. A BS 3621 mortice deadlock on a timber door starts from £150 fitted. A 3-star anti-snap cylinder on a uPVC door starts from £150 fitted, and a straightforward lock change from £90. I say the price before I start, never after, and there’s no call-out fee. The full list is on the BS 3621 lock change page and the price list. Those are starting prices, and the one we agree on the phone is the one you pay.
What if I rent, or I’m the landlord?
The building’s insurance is usually the landlord’s, and the lock condition in it is the landlord’s to meet, which is why so many managing agents ask for BS 3621 or 3-star as standard on a change of tenancy. A tenant’s contents policy can carry its own lock condition, so it’s worth both sides reading their own wording. In flats and shared houses the inside of the door often needs to open without a key, so on a timber door that’s usually BS 8621 rather than 3621; check what the fire risk assessment asks for. I’ve written more for landlords in what landlords must know about locks and insurance.
The mistakes I keep seeing
- Ticking “yes, BS 3621 locks” on the quote form to get the discount, without checking. The discount is small. The gap it opens is not.
- A lovely new composite door with the cheapest cylinder the fitter had on the van. The door is rated. The barrel isn’t.
- A BS 3621 lock on the front and a bolt on the back. The back door is the one that gets tried.
- Keys left in the inside of the lock overnight, next to a letterbox or glass panel.
- Believing the phrase “insurance approved” on a website. Nobody approves locks for insurers. Look for the standard, not the slogan.
FAQ
Is there such a thing as an insurance approved lock?
No. Insurers don’t approve locks. Policies name a standard, usually BS 3621 for mortice locks and a rated cylinder (TS 007 3-star or Sold Secure Diamond) for uPVC doors. A lock either meets the standard or it doesn’t.
Does a Yale night latch meet BS 3621?
A standard night latch doesn’t. There are British Standard night latches that do, and they say so on the case. If the policy says BS 3621 and you’ve only got a night latch, add a mortice deadlock beneath it or swap the latch for a rated one.
Do back doors and patio doors have to comply too?
Under most wordings, yes. “Final exit doors” means every door you can leave the house by, not just the one with the number on it.
Will fitting these locks lower my premium?
Sometimes a little, and only if you tell the insurer. The real value is a claim that goes through without an argument. Treat any discount as a bonus.
Can you tell me if my locks meet the standard?
Yes. Send a photo of the door edge and cylinder to 07453 327708 and I’ll tell you what you’ve got and what, if anything, it needs. Or book the free home security check and I’ll go round every door and window with you.
I’ve had a claim questioned over my locks. What now?
Ask the insurer in writing which condition they’re relying on and where it appears in your policy. If you think they’re wrong, the Financial Ombudsman Service handles complaints free of charge. I can’t advise on the claim, but I can put the locks right so it never happens twice.
One last thing. Nobody enjoys reading a policy. Five minutes with the search box tonight beats finding out the hard way after someone’s been through the back door. If you’d rather I looked, give me a ring. 07453 327708. Even if it’s not me you use, I’ll tell you straight what you need.
Bugsy, KeyWise 24hr Locksmiths, Hythe, Southampton.
Bugsy Edwards
Founder, Keywise 24hr Locksmiths. Family-run on the SO45 Waterside.
This advice comes from a working locksmith, not a content writer. Bugsy answers his own phone, and was recognised at the Hampshire and Isle of Wight PCC Awards 2024. 5.0 from 316 Google reviews.
Call 07453 327708