Most UK home insurance policies require at least one lock on your final exit door to meet British Standard BS3621. Without compliant locks, your insurer may refuse a claim following a burglary or reduce the payout significantly. Knowing how to identify insurance-approved locks helps you verify compliance and identify upgrades needed.
What Is BS3621?
BS3621 is the British Standard for thief-resistant locks. Locks meeting this standard have been independently tested for resistance against picking, drilling, force and manipulation. They feature hardened steel components, anti-pick mechanisms and robust construction that significantly exceeds basic lock specifications.
Insurance providers recognise BS3621 as the minimum acceptable standard for final exit door locks on most UK properties. Some policies may require additional security measures, but BS3621 compliance is the baseline.
Identifying BS3621 Locks
BS3621-approved locks carry distinctive markings that make identification straightforward:
- The kite mark: Look for the British Standards Institution kite mark, a heart-shaped symbol with "BS" inside, stamped on the lock faceplate or cylinder
- Standard number: The marking "BS3621" should be clearly engraved on the lock body
- Number of levers: BS3621 mortice locks are five-lever locks. The packaging or faceplate will indicate "5 lever"
- Anti-drill features: BS3621 locks incorporate hardened steel pins or plates that resist drilling
Checking Your Current Locks
To check whether your existing locks are insurance-approved, follow these steps:
For mortice locks: Open the door and examine the lock faceplate on the door edge. Look for the kite mark and "BS3621" engraving. Five-lever sashlocks and deadlocks should have these markings clearly visible.
For euro cylinders: Look for the BS kite mark on the cylinder body. Additionally, check for British Standard TS007 or SS312 Diamond ratings, which indicate anti-snap protection. Standard euro cylinders without these marks are unlikely to be insurance-compliant.
For rim cylinders: These are less commonly used on final exit doors. If fitted, check for BS3621 markings on the cylinder body or nightlatch case.
What If Your Locks Are Not Compliant?
If your locks lack BS3621 markings, you should upgrade them as soon as possible. The cost of upgrading is modest, typically £80 to £180 per lock fitted, and is far less than the financial risk of an invalidated insurance claim.
Contact a professional locksmith for a compliance survey. They can identify which locks need upgrading, supply approved replacements and install them correctly. They will also provide documentation that you can share with your insurance provider.
Additional Insurance Requirements
Some insurers require more than BS3621 locks. Common additional requirements include:
- Window locks on all accessible opening windows
- A professionally installed burglar alarm system
- External security lighting
- Security grilles or shutters on vulnerable doors
Keys4U Compliance Service
Keys4U Locksmith offers free insurance compliance checks. We examine every lock in your home, identify any that do not meet BS3621, and provide upfront quotes for approved replacements with full documentation for your insurer.
Do not leave your insurance cover at risk. Contact Keys4U Locksmith for a compliance check and upgrade your locks to approved standards today.
