Most people discover the small print in their home insurance at the worst possible time: after a break-in, when a claim is questioned or refused over the locks on the door. It is one of the most common reasons burglary claims run into trouble, and it is entirely avoidable. This guide answers the two questions that actually matter — what locks your insurer expects you to have, and what your policy will and will not pay for when it comes to lockouts, lost keys and lock damage. (It is general information, not insurance advice: policies differ, so always check your own wording.)
There is no law requiring particular locks, but nearly every UK home insurance policy makes them a condition of cover. The benchmark almost everyone refers to is BS3621 — the British Standard for thief-resistant locks on final exit doors, tested against picking, drilling and forced entry. When a policy says locks must be "to British Standard" or meet "approved minimum security," that is BS3621 it is talking about.
In practice insurers typically expect one of two things on each external door: a five-lever mortice deadlock to BS3621 on timber doors, or a key-operated multipoint locking system (engaging at least three points) on uPVC and composite doors, which most modern doors already have. You can check your own in seconds: open the door and look at the lock's faceplate on the door edge for the BSI Kitemark (a heart-shaped symbol) and the wording BS3621 with a year. Our plain-English guide to British Standard locks shows exactly what to look for.
A couple of useful distinctions: BS8621 covers locks that need a key to enter but only a thumb-turn to leave (common in flats, for safe escape), and BS10621 covers locks that can only be deadlocked from outside. Sliding patio doors and French doors often need extra measures — anti-lift devices or top-and-bottom bolts — to satisfy a policy.
Here is the part that catches people out. If your home is burgled and your locks did not meet the standard your policy required, an insurer can decline the claim — even if the burglar did not enter through the door with the sub-standard lock. The condition applies to the property, not just the point of entry. It is one of the most frequently cited reasons claims are challenged or refused.
This is also why who fits your locks matters, not just which lock you buy. A cheap cylinder fitted by an untrained operator can fail on two counts at once: it may not meet the standard your insurer requires, and it may be poorly fitted enough to fail anyway. Using a qualified locksmith who fits genuine insurance-rated parts — and keeping the invoice that states the standard fitted — protects both your door and your cover. One related trap: if you leave a home unlocked, or someone enters using a copy of your key so there is no sign of forced entry, many policies will not pay out at all.
Read your policy's wording on locks (look for "British Standard" or "approved minimum security"), check your door faceplates for the Kitemark and BS3621 marking, and keep any locksmith invoice that records the standard of lock fitted. That paper trail is what settles a claim quickly.
Generally, no — not under a standard policy. Being simply locked out, with the keys sitting on the kitchen table, is not something buildings or contents insurance normally pays for. Where cover exists, it comes through an optional home emergency add-on, which gives you a 24/7 helpline and, in many cases, sends an approved locksmith to get you back in. If you want that safety net, it is worth checking whether your policy includes it or offers it as an extra — rather than assuming you are covered and finding out at midnight.
The distinction insurers draw here is between losing keys and having them stolen. Lost keys are usually not covered as standard — insurers tend to treat misplacing them as down to you. Stolen keys are more often covered, especially if you report the theft to the police and get a crime reference; if a bag is stolen with your keys inside, replacing the locks may well be covered.
Many insurers offer key cover (sometimes called key care) as an add-on, which pays for replacing lost or stolen keys, fitting new locks where there is a security risk, and the locksmith's charges — typically up to an annual limit in the region of £1,000–£1,500. Either way, there is a security point that outranks the money: if a key is genuinely lost or stolen, change or rekey the affected locks promptly, because a missing key plus your address is a real risk — and a burglary with no forced entry is exactly the scenario an insurer may refuse. Our guides on changing locks when moving house and when to change your locks cover when it is worth doing.
If a burglar or attempted intruder damages your locks forcing entry, that damage is normally covered as part of the incident under contents or buildings insurance — report it to the police, get a crime reference, and photograph the damage before anything is repaired. The same goes for locks damaged by an insured event such as a storm or fire, which are usually picked up as part of the wider repair. What is not covered as standard is accidental damage — snapping a key in the cylinder, or damaging a lock during DIY — which needs a separate accidental-damage add-on. If you have just had a break-in, our guide on what to do after a break-in walks through the right order of things.
A named, vetted master locksmith covers your area — no call-out fee.
Pulling it together, a short routine keeps you both secure and covered:
If you are not sure whether your locks meet your insurer's standard, the quickest answer is to have someone qualified look. Every LocksmithLocal locksmith can check your doors against the common policy requirements and fit insurance-rated locks correctly, with an invoice that records the standard fitted — find your local locksmith to arrange it.
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