Home security
Your locks and your insurance claim: the two clauses that catch people
Non-compliant locks are one of the most common reasons a burglary claim is refused — even when the burglar came in somewhere else. How to check your door in sixty seconds.
Most people find out what their home insurance required of their locks after a burglary, which is exactly the wrong time.
Two clauses do nearly all the damage. Both are checkable this afternoon, and neither takes long.
The one that surprises people most: if your locks do not meet the policy's standard, an insurer may refuse a claim even if the burglar did not come in through that door. The requirement is a condition of cover for the whole property, not a description of the route in.
Clause one: the lock standard
Most UK home insurance policies specify a lock standard on external doors, and the benchmark almost all of them use is BS 3621 — the British Standard for thief-resistant, key-operated deadlocks.
Non-compliant locks are one of the most common reasons a burglary claim is turned down.
What BS 3621 actually requires
It is not a marketing badge. The standard sets minimum, tested requirements, including:
- A bolt throw of at least 13mm
- Anti-pick, anti-drill and anti-saw features
- A hardened steel bolt
- A keyway built to resist manipulation
The lock is independently tested against the attacks burglars actually use.
How to check yours, in sixty seconds
Open the door and look at the faceplate on the edge, not at the handle or the keyhole.
A genuine compliant lock is marked there. Look for:
- The BSI Kitemark — a heart-shaped logo
- The text BS 3621
- A year
Embossed or laser-etched into the metal. If those three are not there, the lock is not BS 3621, whatever anyone told you when it was fitted.
Go and look now. It takes a minute and it is the single most useful thing on this page.
What if you have a uPVC or composite door?
Those usually have a euro cylinder and a multipoint mechanism rather than a mortice deadlock, so BS 3621 may not be the relevant standard for your door.
Policies increasingly reference cylinder standards instead — TS007 3-star or Sold Secure Diamond. Those are the ratings to look for, and they are worth having regardless of what the policy says, because a cheap unrated cylinder can be snapped. See anti-snap locks explained.
Read your own policy wording, not a locksmith’s summary of it. The document is the only version that counts at claim time.
Clause two: “forced entry”
The quieter one, and it catches more people than the lock standard does.
Many policies pay out only where there is evidence of forced entry. If a burglar walked in through an unlocked door or an open window, the claim can be refused — the locks were perfect and irrelevant, because they were not engaged.
Two practical consequences:
A lock only counts when it is locked. A nightlatch on the latch is not deadlocked. On a uPVC door, the handle being up is not the same as the key being turned. If the policy says the property must be secured when unoccupied, that is a condition, not a suggestion.
Keys used to enter may not count as forced entry. Which brings in a related problem — see our guide to key safes and insurance.
The mistakes that cause refused claims
Beyond the two clauses, these are the recurring ones:
- Assuming a “high security” lock is a compliant lock. Marketing words have no standard behind them. Only the marking counts.
- A locksmith fitted “an insurance-approved lock” and nobody checked. Ask for the standard in writing on the invoice, and keep the packaging.
- Locks that met the standard when fitted and have since been changed — by a previous owner, a landlord, or a well-meaning relative.
- Back doors, side doors and French doors. The requirement usually covers all external doors, not just the front.
- Window locks. Many policies specify these too. Read the wording.
- Not securing the property when out. The most common of all.
What to do this week
- Read the security conditions in your policy. Two minutes. Search the document for “lock”, “security” and “forced”.
- Check the faceplate on every external door. Kitemark, BS 3621, year.
- Check your euro cylinders for a TS007 or Sold Secure marking.
- Fix any gaps as a booked daytime job, not an emergency. Roughly half the price. See what it should cost.
- Keep the paperwork — invoice naming the standard, and the packaging.
And if a claim has already been refused
An insurer’s decision is not the end of the process.
- Ask for the refusal in writing, quoting the exact policy clause relied on.
- Use the insurer’s own complaints procedure first. You must, before escalating.
- Then take it to the Financial Ombudsman Service. Free, independent, and it can overturn an insurer’s decision. Time limits apply, so do not sit on it.
- Get free advice from Citizens Advice.
The honest summary
Insurers are not looking for reasons to refuse, but the conditions are real and they are enforced. The whole of your exposure here comes down to three things:
Does the faceplate say BS 3621? Are your cylinders rated? Was the door actually locked?
Sixty seconds of checking now beats an argument you cannot win later.
General information for the UK, not insurance or legal advice, and it cannot see your policy. Policy wordings differ significantly between insurers — yours is the one that counts. Checked 27 August 2026.