BS3621 Locks & Home Insurance in Dunchurch — What You Need to Know

BS3621 is the British Standard for five-lever mortice deadlocks. It's a testing standard maintained by the British Standards Institution that specifies how much resistance a lock must offer against picking, drilling, saw attacks, and forced entry. Only locks that pass all the required tests can carry the BS3621 kitemark.

The number 3621 refers to the specific standard document. Five-lever means the lock contains five internal levers that all need to be aligned correctly by the key before the bolt will move — this is what makes these locks so difficult to pick compared to a standard two-lever lock. A BS3621 lock also has a hardened steel bolt and anti-drill pins to resist common attack methods.

The key thing to know is that a Yale nightlatch — however good the brand — is NOT a BS3621 lock. Neither is a basic euro cylinder on its own. BS3621 refers specifically to five-lever mortice deadlocks fitted into the body of the door. If your policy says "BS3621", it means this specific type of lock.

Almost certainly yes, if you have standard home insurance. The vast majority of home and contents insurance policies issued by mainstream UK insurers specify BS3621 five-lever mortice deadlocks on all final exit doors as a condition of cover. This isn't a recommendation — it's a policy condition, meaning that if you make a claim following a burglary and you didn't have the required locks, your insurer may reject the claim or reduce the payout.

This is particularly important to understand because many people in Dunchurch have made improvements to their homes over the years — fitted new uPVC doors, replaced windows, changed locks — without specifically verifying that the new locks meet the BS3621 standard. A new lock isn't automatically a BS3621 lock. It has to carry the mark.

If you're in CV22 and you're not sure whether your policy has this requirement, look in the policy schedule or policy conditions document under "security" or "property conditions". If you find a reference to BS3621, five-lever mortice locks, or insurance-approved locks, you need to check whether your current locks meet that standard.

The simplest way to check is to look at the faceplate of your mortice lock — that's the metal plate you can see in the edge of the door when the door is open. A BS3621 compliant lock will have "BS3621" stamped or engraved on the faceplate. If that marking isn't there, the lock doesn't meet the standard.

If you have a uPVC door with a euro cylinder, check whether the cylinder is a standard or anti-snap model. Standard cylinders that protrude beyond the door face are not BS3621 compliant on their own — the multipoint mechanism they work with provides additional security, but the cylinder itself needs to be at minimum a 3-star TS007 anti-snap model to meet most insurers' requirements.

If you're genuinely unsure and you're in Dunchurch, call me on 07735 336175. I'll check your locks and tell you clearly whether they meet the standard. There's no charge for the assessment when I'm in CV22 for other work.

Supply and fit of a BS3621 five-lever mortice deadlock in Dunchurch starts from £79. This includes the lock, fitting, and new keys — everything you need. There is no VAT on this price, and there is no call-out fee on top. If you need both front and back doors done at the same visit, the second lock is £69 as the call-out and setup time is already covered by the first.

The price covers standard timber doors with existing mortice lock cases. If your door has never had a mortice lock and needs a fresh case cut, that adds to the time and cost — I'll advise you of this before I start. Most Dunchurch properties built before 2000 already have a mortice case; the question is whether the lock inside it meets BS3621.

I carry ERA Fortress and Union branded BS3621 locks in my van. Both are well-regarded UK manufacturers with locks that are consistently BS3621 certified. I can show you the certification on the packaging before I fit the lock.

Beyond the front and back door locks, some insurance policies in Rugby also require window locks on accessible windows. This typically means any window within 2 metres of ground level, or within reach from an outbuilding, fence, or extension roof. Key-operated window locks are what insurers typically specify — not just catches or latches that can be opened without a key.

For uPVC doors specifically, anti-snap euro cylinders (3-star TS007 rated) are the insurance-preferred upgrade. Brands I regularly fit in Dunchurch include Avocet ABS and Yale Platinum. The Avocet ABS comes with a £2,000 insurance guarantee against cylinder snapping attacks, which some insurers recognise specifically.

If you want a full security review for your Dunchurch property — covering all doors and accessible windows — I'm happy to do this when I'm in CV22. I'll give you a complete picture of what you have, what you need, and exactly what it would cost to bring everything up to insurance standard. Call 07735 336175 to arrange.