Do You Need BS3621 Locks for Your Home Insurance to Be Valid?

What Is the BS3621 Standard and Why Do Insurers Care About It?

BS3621 is a British Standard published by the British Standards Institution (BSI). It sets minimum security requirements for thief-resistant locks fitted to external doors. To carry the BS3621 kitemark, a lock must withstand a set of physical attacks including picking, drilling, sawing, and manipulation.

Insurers care because locks meeting this standard are statistically harder to bypass. When a policy includes a BS3621 condition, the insurer is essentially saying: if your locks don't meet this standard, we consider the property insufficiently secured and may reduce or refuse a claim.

Many South London homes built before 2000 still have older locks that were never certified to BS3621. This is one of the first things our South London locksmith team checks when we carry out a security inspection.

Do I Need BS3621 for Home Insurance in the UK?

The honest answer: it depends on your policy. There is no blanket UK law requiring BS3621 locks. But many home and contents insurance policies — particularly from mainstream insurers like Aviva, LV=, and Direct Line — include phrases like "all external doors must be secured with a five-lever mortice deadlock conforming to BS3621" in their conditions of insurance.

The safest approach is to read your policy wording carefully. Look in the "security requirements" or "conditions" section. If it mentions BS3621, you need compliant locks on all final-exit doors — typically the front door and back door.

If you're not sure whether your locks meet the standard, call us. Our Level 3 City & Guilds locksmiths can inspect your locks on the same day and advise whether you need to upgrade. We offer fixed-price lock changes across South London with no call-out fee.

How to Check If Your Current Locks Are BS3621 Compliant

The easiest way to check is to look for the BS3621 kitemark — a small logo stamped on the lock body, faceplate, or keyhole cover. It looks like a kite shape with "BS3621" printed on or near it. If it's there, your lock is certified.

If there's no kitemark, note down the brand name and model number (usually on the faceplate or internal mechanism) and search online. Most lock manufacturers publish a list of their BS3621-certified products. Common certified brands include ERA, Yale, Chubb, and Union.

What Happens If You Claim Without BS3621 Locks?

If your policy lists BS3621 as a requirement and your locks don't comply, the insurer can treat this as a breach of a policy condition. In practice, this means they may reduce your payout, apply a proportional reduction, or refuse the claim entirely — depending on whether they decide the lack of compliant locks contributed to the loss.

This is especially common in burglary claims. If a burglar bypassed a non-BS3621 lock to gain entry, the insurer has grounds to argue the property was not adequately secured. Don't let a substandard lock cost you thousands. Upgrading is cheap compared to a refused claim.

BS3621 Mortice Deadlock vs BS3621 Euro Cylinder — What's the Difference?

A BS3621 mortice deadlock is a five-lever lock fitted inside the door. When locked, it throws a solid bolt into the door frame, making the door extremely difficult to force. This type is most commonly found on traditional timber front and back doors across South London.

A BS3621 euro cylinder is the cylinder component that fits inside a multipoint locking system — common on uPVC and composite doors. The cylinder itself must carry the BS3621 certification. Critically, if you have a multipoint lock, insist on a cylinder that is also anti-snap rated — standard cylinders are vulnerable to cylinder-snapping attacks even if they carry BS3621.

A good rule of thumb: traditional timber door = BS3621 mortice deadlock. Modern uPVC or composite door = BS3621 anti-snap euro cylinder inside a multipoint system.

How Much Does a BS3621 Lock Installation Cost in South London?

We offer fixed-price BS3621 lock installations across South London with no call-out fee. A standard BS3621 five-lever mortice deadlock supply and fit starts from £135, depending on the lock model chosen. Premium anti-snap BS3621 euro cylinders are priced similarly.

All our pricing is agreed upfront — no surprises on the invoice. We carry a range of BS3621-certified locks from ERA, Yale, and Chubb. If your insurer requires a specific brand or rating, just mention it when you call and we'll confirm availability.

We cover all South London postcodes including SW, SE, CR, SM, and BR. As a 24-hour locksmith, we can fit your BS3621 locks the same day — no waiting, no hidden fees, and a written receipt you can provide to your insurer as proof of installation.