Home Insurance Lock Requirements | How to Check Before Your Claim Gets Rejected

Your front door gets kicked in. You call the police, then your insurer. The loss adjuster visits, looks at your door, and asks which lock was fitted. You show them the cylinder you had replaced six months ago. They note it down. Two weeks later, a letter arrives explaining your claim is being disputed because the lock doesn't meet the standard specified in your policy schedule.

This happens. Not constantly, not to every claimant, but enough that I see the aftermath regularly on Crawley call-outs where someone rings us to fit a replacement after a break-in and mentions, almost in passing, that the insurer is "being difficult". The difficult part usually traces back to a clause they'd never read.

So here's what those clauses actually say, what the standards behind them mean in practice, and how to check your own property before you ever need to find out the hard way.

---

What Your Policy Schedule Actually Says

Most home insurance policies don't just say "fit a decent lock". They specify a standard, usually one of the following:

• BS3621 or BS8621: the British Standard for key-operated deadlocks and deadlatches
• TS007 3-star: the Secured by Design cylinder standard
• PAS24: the performance standard for complete doorsets, including the frame and hardware
• SS312 Diamond Grade: Sold Secure's highest cylinder rating
• A combination, such as a BS3621 mortice lock plus a TS007 3-star cylinder on the nightlatch

Some policies add wording around window locks, final exit doors, and outbuildings. Some policies from insurers serving areas with higher-than-average burglary rates (certain RH10 postcodes fall into this category depending on the underwriter) specify additional requirements.

The problem is that most policyholders read the headline premium and the excess. The schedule of conditions, the bit that lists what you must have fitted, sits in the back pages and gets skimmed or skipped entirely.

Action: get your policy schedule out now. Search the PDF for the words "lock", "BS3621", "deadlock", or "security condition". If you don't have it electronically, call your insurer and ask them to read out the security requirements. Take notes.

---

BS3621 and BS8621: What the Standard Actually Tests

BS3621 is the one you'll see most often. It covers key-operated locks: five-lever mortice deadlocks and sashlock variants. The standard tests:

• Bolt throw of at least 14 mm
• A minimum of 1,000 key differs (how many distinct key patterns exist, making it harder to open with a similar key)
• Hardened steel bolt that resists cutting
• Anti-saw pins in the bolt to defeat a hacksaw
• A deadlocking mechanism so the bolt can't be pushed back without the key

BS8621 covers the same physical performance but adds a thumbturn on the inside, so the door can be opened from the inside without a key. That matters for fire escape routes.

A five-lever mortice lock that passes BS3621 will have the kitemark stamped on the forend plate and on the faceplate. If your lock doesn't have the kitemark, it doesn't qualify, regardless of what the packaging said or what the previous owner told you.

Check: look at the metal plate visible on the edge of your door when it's open. Find the kitemark, a small crowned symbol followed by BS3621 or BS8621. No kitemark, no compliance.

---

The Final Exit Door Clause

This one catches people out more than any other. A final exit door is, in insurance terms, any external door that can only be operated with a key from both sides. The idea being that when you leave the property, you lock it with a key, and from the outside there's no way to open it without one.

Many policies require that every external door functions as a final exit door. Which sounds obvious until you consider:

• A thumb-turn cylinder on a uPVC door lets anyone inside open the door without a key. If someone breaks a window panel, reaches in, and turns the thumb-turn, they're in. Some insurers specifically exclude thumb-turn cylinders for ground-floor and accessible doors on this basis.
• A nightlatch without a deadlocking snib can be pushed back with a piece of plastic. It isn't truly deadlocked, so it doesn't count as a final exit lock under a strict reading.
• Patio doors and bifold doors with a single multi-point locking handle that can be operated from the inside without a key fail the same test.

Policies differ on whether they require a final exit mechanism on every door or just the "main" or "principal" entrance. Read yours carefully. If it says "all external doors shall be fitted with a five-lever mortice deadlock to BS3621", that includes the kitchen door onto the garden, the back gate door, and the garage side door.

Check: go to every external door in the property. Try to open it from the inside without using a key. If you can, it may not meet a final exit requirement. Note which doors fail and cross-reference with your policy wording.

For uPVC doors, the cylinder is the relevant control point. A thumb-turn cylinder (common on newer installations because it's convenient) may need to be swapped for a key-both-sides cylinder on ground-floor doors if your policy demands final exit compliance. Ultion and Avocet ABS both make key-both-sides variants in TS007 3-star. A cylinder swap on a standard uPVC door in Crawley typically costs £60 to £100 fitted, depending on the cylinder specified.

---

The Like-for-Like Replacement Trap

A locksmith (not us) does an emergency call-out in Maidenbower after a lock fails. The homeowner asks for a like-for-like replacement. The locksmith fits a replacement cylinder that looks identical to the original. Job done. Except the original was a TS007 3-star anti-snap cylinder, and the replacement is a standard euro cylinder from a trade pack, no star rating, no anti-snap protection.

From the outside the door looks the same. The key works. The homeowner has no reason to suspect anything is different. Then there's a break-in six months later, the insurer checks the fitted cylinder, it's not TS007 3-star as required by the policy, and the claim is complicated.

This isn't an argument about whether locksmiths in general are careless. It's a specific structural problem: emergency call-outs happen fast, the pressure is to get the door working, and if the customer doesn't know to ask for a rated cylinder, and the operative doesn't check the policy requirement, the replacement can be compliant-looking but non-compliant in fact.

The same trap appears when homeowners buy replacement cylinders themselves from a DIY shed. Plenty of cylinders on the shelf at a Crawley Screwfix or B&Q carry no star rating whatsoever. The packaging might say "anti-snap" without specifying which standard was tested. TS007 3-star cylinders must pass three independent tests: anti-snap (TS007), pick resistance (to EN1303), and drill resistance. A cylinder that just says "anti-snap" on a card in a blister pack has passed nothing you can verify.

What to ask when booking a locksmith: "What star rating is the cylinder you'll be fitting, and can you confirm it's TS007 3-star?" Any locksmith who can't answer that question immediately is worth questioning further.

What to ask when buying your own: Look for the TS007 3-star mark on the cylinder body itself, not just the packaging. Avocet ABS, Ultion, Mul-T-Lock MT5+, and the Yale Superior range all carry verifiable third-party certification.

---

Window Lock Clauses

Window lock requirements vary more between policies than door lock requirements do. Common formulations include:

• "All accessible ground-floor windows must be fitted with key-operated locks"
• "All windows within two metres of a flat roof, drainpipe, or other climbing aid must be key-operated"
• "All windows that can be opened from the outside to allow entry must be secured by key-operated locks when the property is unoccupied"

A standard uPVC window with a cockspur handle or a friction stay and no additional lock doesn't usually satisfy a key-operated requirement. The multi-point locking that engages when you lift the handle and close the window is internal only. An intruder who breaks the glass and reaches in can release the handle without a key.

Key-locking handles, which are standard handle replacements that require a key to open, solve this at low cost. ERA, Mila, and Roto all make versions compatible with common uPVC profiles. Expect to pay £15 to £30 per handle, plus fitting time if you're not comfortable with the installation.

For older timber-framed windows in properties around Northgate, Gossops Green, or parts of Ifield where the housing stock is older, the requirement might be satisfied by surface-mounted window locks with key operation, such as the Chubb 8K114 or similar. These screw into the frame and the sash.

The flat-roof clause catches people in Broadfield and Tilgate especially, where some 1970s and 1980s layouts include garage roofs or single-storey extensions directly below first-floor windows. If your insurer's wording references "accessible" windows and your first-floor bedroom window sits above a flat roof, it may count as accessible regardless of floor level. Check.

Check: stand outside your property and identify every window that a person of average fitness could reach from ground level, a garden wall, a bin, a flat roof, or a drainpipe. For each one, ask whether it has a key-operated lock. If not, your policy may require one.

---

What "Maintained in Good Working Order" Actually Means

Many policies include a condition that security measures must be "maintained in good working order" and that specified locks must be "in use" when the property is unoccupied or at night. Both clauses have teeth.

A five-lever mortice deadlock that's been jamming for six months and is habitually left unengaged because it's awkward to operate counts as not in use. If a break-in occurs and the loss adjuster determines the lock wasn't engaged (jemmied frames leave evidence of whether the lock was thrown), the claim can be reduced or declined under this condition.

A uPVC door where the multi-point locking mechanism doesn't fully engage because the door has dropped and the hooks don't align properly is, in operational terms, not locked. The handle lifts, the mechanism cycles, but the bolts don't seat. From the inside it feels locked. From a structural perspective, the door is held only by the latch.

Both of these failure modes are avoidable and both are things you can check in ten minutes:

• Mortice deadlock: turn the key and watch the bolt extend fully. Two full turns on a BS3621 lock. The bolt should move smoothly with no grinding. If it doesn't, the lock needs attention before it fails entirely.
• uPVC multi-point: lift the handle fully, engage all locking points, then try to push and pull the door from outside. Any movement at the frame edge suggests the hooks aren't seating. A door that rattles in the frame in Crawley's winter wind is a door that isn't locking properly.
• Window handles: test that the key-locking function works. Handles that look identical to key-locking versions are sometimes fitted without the locking cylinder installed, because the installer ran out or the part wasn't included. Turn the key. The handle should be immovable without it.

---

How to Document Compliance Before You Need It

If you ever do claim, having a paper trail of what was fitted and when is far better than relying on memory or the word of the installer.

Do this:

1. Photograph every external door lock, cylinder, and window lock now. Include close-ups of any certification stamps.
2. Keep the receipts or invoices for any lock upgrades. A receipt from a locksmith that specifies "Ultion 3-star TS007 cylinder, 45/45mm, fitted to front door" is useful evidence.
3. If a locksmith fits your locks, ask for a written job sheet listing the products installed by name and standard. A reputable firm won't hesitate.
4. When you renew your policy, read the security conditions again. Standards in policies can change at renewal. A policy you took out five years ago may now have tighter requirements than it did then.
5. If you've recently moved into a property in Pound Hill, Bewbush, or anywhere else in the RH10 to RH11 area, don't assume the previous owner's locks are compliant. Change the cylinders as a matter of course (you don't know who has a key copy) and use that moment to fit rated ones.

---

A Note on Rental Properties in Crawley

Landlords have an additional layer to think about. If your buy-to-let in Three Bridges or Horley is insured under a landlord policy, the security conditions in that policy apply to the property as let. If a tenant replaces a lost key and in doing so has a copy cut from a cylinder that a locksmith later finds is non-compliant, the insurance condition may not have been maintained.

Some landlord policies also require that any security upgrades are carried out by a suitably qualified person. That's not always defined, but "suitably qualified" in this context generally means someone who can provide a job sheet and evidence of the product fitted.

If you're managing a property remotely from Reigate or Redhill and relying on a letting agent in Crawley to handle maintenance, make sure the agent's contractor list includes locksmiths who understand rated cylinders and can produce paperwork. It's a reasonable thing to ask. Any contractor worth using will confirm it without hesitation.

---

Quick Reference: Compliance Check by Door Type

---

If you've gone through the checks above and found something that doesn't comply, or you're not sure what standard a lock meets, we cover Crawley and the surrounding RH postcodes and aim to be with you in under 30 minutes for urgent calls. For non-urgent assessments we can tell you on the call what a compliant upgrade is likely to cost, without any obligation to book. Pricing is confirmed before anything is touched.