A guide to insurance approved locks should start with one practical point: there is no single lock that suits every door, every insurer or every property. The right upgrade depends on your door type, how it locks, whether it is a final exit door and the wording of your home insurance policy. Getting that detail right can improve security without paying for hardware that does not solve the real problem.
For homeowners in Bristol and South Gloucestershire, insurance requirements often come up after moving house, renewing a policy or following a burglary. A local locksmith can assess the existing door, explain what the insurer is likely to require and fit an appropriate lock properly – rather than simply replacing parts that are still serviceable.
What does insurance approved actually mean?
“Insurance approved” is commonly used to describe locks that meet recognised security standards or the minimum security conditions set out by an insurer. It does not mean every insurer automatically accepts every lock carrying a British Standard mark.
Your policy may specify the type of lock required on external doors. Older policies sometimes ask for a five-lever mortice deadlock conforming to British Standard BS 3621 on timber doors. Others refer more generally to a lock meeting a British Standard, or require suitable security on all external access doors.
The sensible approach is to check the policy schedule and any endorsements. Look for wording about door locks, windows, forced entry and unoccupied periods. If you are unsure, ask the insurer what standard they require for your particular door. Keep any invoice after work is completed, as it provides a clear record of the lock fitted.
The main standards you are likely to see
BS 3621 mortice deadlocks
BS 3621 is the standard most people mean when they refer to an insurance-approved mortice lock. It is usually a five-lever mortice deadlock fitted into a solid timber door. A compliant lock is marked with the British Standard kite mark and typically has a key-operated deadbolt.
These locks are designed to resist common forms of forced attack better than basic mortice locks. They are often used alongside a rim nightlatch on a front door: the nightlatch provides everyday convenience, while the mortice deadlock is secured when the property is left empty or overnight.
A BS 3621 lock is not automatically the right answer for every household. Because it requires a key to open from inside, it may not be suitable where a simple, key-free escape route is needed. That is particularly relevant in shared homes, rental properties and households where an occupant may struggle to locate a key in an emergency.
BS 8621 and emergency escape
BS 8621 locks offer similar security performance but are designed to be opened from inside without a key, commonly by a thumbturn. They can be a better choice where safe exit is a priority.
However, not every insurer treats BS 8621 in exactly the same way as BS 3621. Before choosing it solely for insurance compliance, check the policy wording. A professional locksmith should also consider the position of nearby glass. If a thumbturn can be reached after breaking a glazed panel, additional protection or a different solution may be needed.
TS 007 anti-snap cylinders
Many uPVC, composite and aluminium doors use a euro cylinder with a multi-point locking mechanism. These doors are not normally fitted with a traditional mortice deadlock, so the security discussion is different.
TS 007 is a recognised standard for cylinders and security furniture. You may see cylinders rated one star or three stars. A three-star cylinder provides the higher level of protection on its own. A one-star cylinder can achieve an equivalent combined rating when used with two-star security door furniture.
This matters because ordinary euro cylinders can be vulnerable to snapping if attacked. An anti-snap cylinder is designed to break in a controlled way while protecting the internal locking section. It is a worthwhile upgrade, but only if it is the correct size and fitted securely with suitable handles.
Multi-point locks and door condition
A multi-point lock engages hooks, rollers, bolts or deadbolts at several points along the edge of a uPVC or composite door. It provides good security when the door is correctly aligned and fully lifted into position before the key is turned.
The cylinder is only one part of the system. If the door has dropped, the keeps are misaligned or the gearbox is failing, the locking points may not engage properly. Forcing the handle can damage the mechanism further. In that situation, repairing the alignment or replacing a faulty gearbox may be more important than fitting a new cylinder.
Choosing the right lock for your door
The door material and construction should guide the decision. On a solid timber front door, a BS 3621 mortice deadlock may be the appropriate insurance-led upgrade. On a uPVC or composite door, a correctly rated anti-snap cylinder, protective handles and a functioning multi-point mechanism are more likely to be relevant.
Aluminium doors, patio doors, French doors and side entrances all need their own assessment. A lock can meet a recognised standard but still be poorly matched to the door, frame or glazing around it. Security is only as strong as the complete installation.
It also depends on how the property is used. A landlord changing locks between tenancies may need a practical solution that supports safe escape and straightforward key management. A shop, office or shared premises may benefit from restricted keys or a master-key system, provided emergency routes remain compliant. A home with a rear door used daily needs a reliable arrangement that people will actually lock correctly.
Common mistakes that can affect security
The most common issue is assuming that a lock marked “five lever” is insurance approved. Five levers alone do not confirm BS 3621 compliance. Check for the appropriate standard marking rather than relying on appearance or an old key.
Another mistake is fitting a high-security cylinder to a door with loose, damaged or poorly fitted handles. The cylinder should not protrude excessively beyond the handle, as this can make it easier to attack. Correct measurement is essential, particularly on doors with thicker security furniture.
Homeowners also sometimes leave a multi-point door on the latch without lifting the handle and turning the key. In that position, the hooks and bolts are not engaged, so the door is not fully secured. If the handle is difficult to lift, do not ignore it. It may be an early warning that the door needs adjustment.
Finally, avoid treating insurance compliance as a one-off purchase. Locks can wear, doors move with age and keys can be lost or copied without your knowledge. After moving into a property, changing external locks is a sensible precaution even if the existing hardware looks secure.
What a proper lock upgrade should include
A proper assessment looks beyond the visible lock. The locksmith should identify the door type, inspect the frame and hinges, check alignment, test the locking mechanism and measure the cylinder accurately. They should then explain the available options in plain English, including any difference between meeting an insurer’s stated requirement and choosing a higher level of protection.
For a timber door, this may involve fitting a correctly positioned mortice lock and checking that the strike plate is securely fixed into sound timber. For a uPVC or composite door, it may mean realigning the door first, replacing a worn multi-point gearbox if required and fitting a suitable anti-snap cylinder with secure handles.
The cheapest replacement is not always the best value. Equally, a full door replacement is rarely the first answer when the issue is a failed lockcase, worn cylinder or misaligned keeps. Repairing the root cause can restore security and save significant expense.
When to call a locksmith
Call for advice if you have moved home, lost keys, suffered attempted forced entry or found that your insurer has asked for an upgrade. Urgent attention is also sensible if a key turns without operating the lock, a handle will not lift, a cylinder is damaged, or a door no longer closes and locks smoothly.
South Gloucestershire Locksmith & Security can inspect the full door and lock arrangement, carry out repairs where possible and recommend an upgrade that fits the property rather than a generic sales pitch. You speak directly to a trusted local locksmith, with clear quotation details before work begins.
If you are reviewing your security after a move or policy renewal, do not wait until a stiff lock becomes a failed one. A short inspection now can give you a clear answer on what your door needs and the confidence that it is properly secured tonight.