Which locks does my home insurance require?
The short answer
Many home insurance policies require final exit doors to have a five-lever mortice deadlock to British Standard BS3621 on timber doors, or a multipoint locking system on uPVC and composite doors, and key-operated locks on accessible windows. The exact wording varies, so check the "security" or "minimum security" section of your own policy.
Key points
- Your policy wording decides. Look for a "minimum security" condition or endorsement.
- Timber front doors: a BS3621 five-lever mortice deadlock is the usual requirement.
- uPVC and composite doors: a multipoint lock with a good cylinder, ideally anti-snap.
- Accessible windows often need key-operated locks.
- Not meeting the conditions can reduce or void a theft claim.
Why it matters
If your policy has a minimum security condition and your locks do not meet it, a theft claim can be reduced or refused, especially where there was no sign of forced entry. Insurers usually ask about locks when you buy the policy, so a wrong answer can cause problems later too.
The standards in plain English
| Standard | What it is | Where you see it |
|---|---|---|
| BS3621 | British Standard for thief-resistant locks that need a key to lock and unlock | Five-lever mortice deadlocks and some nightlatches on timber doors |
| BS8621 | Similar, but can be opened from inside without a key | Homes where quick escape matters, such as flats |
| Multipoint lock | Locks the door at several points along the frame | uPVC and composite doors |
| TS007 3-star or SS312 Diamond | Tested cylinders that resist snapping, picking and drilling | The key cylinder on uPVC and composite doors |
| PAS 24 | Security standard for complete doors and windows | New doors and windows |
A BS3621 lock is usually stamped with the British Standard number and the Kitemark on the faceplate, the metal strip you see on the edge of the door when it is open.
Checking your own doors
- Find the security section of your policy and note exactly what it asks for on final exit doors, patio doors and windows.
- Open each external door and look at the lock faceplate for a BS3621 or Kitemark stamp.
- On uPVC doors, check the cylinder for a TS007 star marking or SS312 Diamond mark. If there is none, an anti-snap upgrade is inexpensive.
- Check patio doors and accessible windows have key-operated locks.
- If you are unsure, ask a locksmith to check. Many will do it while fitting something else.
Tenement flats
In a Glasgow tenement, your "final exit door" is usually the door of your flat, not the main close door, which is shared. Many tenement flat doors are original timber with an old rim lock or nightlatch. Adding a BS3621 mortice deadlock is a common and relatively cheap upgrade. Fitting an anti-snap cylinder costs around £125 to £175 according to national price guides.
If you rent, the landlord is usually responsible for the locks on the property. Ask before changing anything.
Getting the work done
Our ranked table of Glasgow locksmiths lists the firms we rate highest. Ask for the lock make and standard on the invoice so you can show your insurer. If you are locked out and need a new lock anyway, read what an emergency lockout should cost first.
Questions
Does a Yale lock meet insurance requirements?
A basic nightlatch on its own often does not. Some nightlatches are made to BS3621 and may be accepted. Check your policy wording and the lock faceplate.
Do I need to tell my insurer if I change my locks?
If the change improves security, it is usually fine. If you are changing to something that may not meet the policy conditions, tell your insurer first.
Do all insurers require BS3621 locks?
No. Requirements vary between insurers and policies, and some have no specific lock condition. Your own policy wording is what counts.
What is an anti-snap lock?
A cylinder designed to resist a common burglary method where the cylinder is snapped to open the door. Look for TS007 3-star or SS312 Diamond markings.
Sources
- Churchill: door lock types and home insurance (opens in a new tab)
- Checkatrade: locksmith prices (opens in a new tab)
- Neighbourhood Watch: door security advice (opens in a new tab)
This guide is general information about Glasgow and Scotland, checked on 3 November 2026. Prices and rules change, so confirm anything important with the organisation named before you act.
