Home Insurance Lock Requirements and What Your Policy Expects

Every home insurance policy is different, which means your policy documents are the only real authority on what locks you need. However, most insurers expect specific lock standards on your external doors and accessible windows to validate your cover. If a burglary happens and the right locks were not fitted or were not used, the insurer can refuse to pay your claim.

If your home is burgled, the insurer will usually ask for evidence of forced entry and a police crime reference number. If the locks that your policy asks for were missing or not used, the insurer may refuse your claim.

Having a high quality lock does not guarantee that your insurance covers you. The Master Locksmiths Association points out that no security device will completely prevent unauthorised entry, and fitting good locks does not oblige an insurer to issue cover.

What most policies expect on front and back doors

The rules for door locks depend heavily on the material your door is made of. Generally, you will need a front door lock that meets the British Standard BS3621, and you may need five-lever mortice deadlocks on all your external doors to get home insurance. Different insurers have different rules.

When you check your external doors, you will normally find one of two setups depending on the material:

• Timber doors usually feature a mortice deadlock or a sashlock, which are locks fitted inside a timber door, often paired with a surface latch.
• Modern uPVC and composite doors use a multipoint locking mechanism, which is the strip of hooks and bolts worked by lifting the handle.
• The central part of that modern mechanism is called the gearbox, and it is operated by a euro cylinder, which is the barrel you put the key into.

If you have several doors, you can ask a locksmith to make them keyed alike. This means multiple locks operate from one single key. This is convenient, but each individual lock still needs to meet the standard for that door, and your policy wording is the place to check.

Timber doors and the BS3621 standard

For traditional external timber doors, it is generally accepted that locks should be certified to BS3621:2017+A1:2024 to comply with the requirements of most insurers. This standard applies to a lever mortice lock with at least five levers. To check if your lock meets this standard, open the door and look at the metal faceplate on the edge. A certified lock shows the BSI Kitemark or a BS3621 stamp on this faceplate. If you are unsure what to look for, our guide on what a 5-lever mortice lock is can help you identify it.

Many older timber doors are fitted with a night latch or rim lock, which is the surface latch often called a Yale lock. This is operated from the outside by a rim cylinder. A night latch should not be the only lock on the door, as insurers prefer the BS3621 standard.

Where escape from fire without a key is required, the MLA says a BS8621 lock assembly should be installed. This type of lock has a key on the outside but a handle or thumb turn on the inside, so you can get out without a key. Written agreement from your insurer is wise.

Security standards for uPVC and composite doors

Multi-point locks on uPVC and composite doors cannot be tested to BS3621. For locks produced before the 2011 PAS standards, the MLA guidelines say the mechanism should have at least three locking points and a suitable cylinder. If your door has a non-standard lock that falls outside these rules, written agreement for acceptance of such locks should be obtained from the insurer.

Because these modern doors are vulnerable to lock snapping, where an intruder breaks the cylinder to bypass the lock, fitting a snap resistant cylinder is the usual upgrade. The Master Locksmiths Association recommends fitting SS312 Diamond cylinders as a cylinder change only solution. Alternatively, you can fit a TS007 one star cylinder combined with a two-star handle, or a TS007 three star cylinder. Either of these TS007 solutions must total three stars to provide the right protection.

You can read more about these ratings in our guide to anti snap locks. When fitting these parts, the outside cylinder must not protrude more than 3 mm from the face of the door or the lock furniture. Cylinders that stick out are more prone to lock snapping, according to the MLA.

Windows, patio doors and outbuildings

Most insurers require key operated window locks on all ground floor and accessible windows. Patio doors are often treated strictly by insurers, with top or bottom locks common but considered weak. If a patio door or ground floor window is smashed during a break in, a locksmith can help with boarding up, which means securing the property temporarily with timber until new glass is fitted.

Which? found in 2025 that almost all policies include cover to replace your external door locks if your keys are stolen, but that window locks are not covered by 63 per cent of policies. Check your own policy wording for window locks.

If your bag is stolen containing both your house keys and your car keys, you will need two different professionals. A domestic locksmith changes the door locks on your house. Auto locksmiths are a separate specialism covering vehicle entry, key cutting, transponder and remote programming.

Using your locks to keep your cover valid

Having the right locks fitted is only half of the requirement. Make sure you always leave your house properly locked up, because otherwise your claim may not be paid. When window locks are engaged, the keys must be removed.

However, you must balance security with fire safety. Keys should be kept within easy reach of the occupant but out of reach of an intruder. Careful consideration must be given to the means of escape in the event of a fire before specifying that locks are engaged and keys removed.

How to check what your policy says

The only way to know your minimum security requirements is to read your home insurance policy documents. Without the required locks you could face a rejected claim later on.

The table below shows common lock types, the security standards they are measured against, and where they are normally used.

Your own policy wording is the final authority and may differ. If you are unsure what it means, ring your insurer to ask.

What to do if your locks do not meet the standard

If your locks fall short of the minimum requirements, you will need to arrange an upgrade. If you own your home, you can simply read up on when to change door locks and book a professional to fit the right standard of cylinder or mortice lock.

If you rent your home, tenants should check their tenancy agreement and get the landlord's agreement before changing locks. A landlord who changes the locks to keep a tenant out without a court order commits illegal eviction, which is a criminal offence. For firm legal advice on evictions or tenancy disputes, you should contact Citizens Advice or Shelter to discuss your own situation.

Getting proof from a locksmith

There is no government licensing of locksmiths in the UK, which means anyone can trade as one. Vetting matters because you are letting a stranger work on your front door. The Master Locksmiths Association (MLA) is the main trade association. Its approved companies are vetted, have criminal record (DBS) checks, employ locksmiths who have passed the MLA exam and are inspected regularly. This is a voluntary approval scheme, not a legal requirement, but an approved locksmith can supply a receipt or certificate showing exactly what standard of lock was fitted to satisfy your insurer. You can read the official minimum security requirements on their website.

Jobs are usually priced as labour plus parts, either by the hour or as a fixed price per job. The price is driven by the time of day, with evenings, nights, weekends and bank holidays costing more. Location also matters, as London and the South East cost more. The type and security grade of the lock will change the parts cost, and how entry is gained affects the labour time. Many locksmiths charge no separate call-out fee but some do, and VAT may or may not be included. Most single lock changes and lockouts take well under an hour.

When you call a locksmith, ask how entry will be gained. A good professional will use non-destructive entry, which means picking or bypassing rather than drilling, whenever possible. Ask what standard the new lock meets, and tell the locksmith to give you a total price, including parts, VAT and any out-of-hours charge, before work starts. Check the business has a real local address, reviews over time, and any MLA approval claim on the MLA's own site. Ask for ID on arrival and a written invoice.

When you are looking for a tradesperson, watch out for these common warning signs:

• National call centres advertising as a local locksmith and passing the job to whoever is nearest.
• A very low price quoted on the phone that multiplies on the doorstep.
• Refusing to give a price before starting the work.
• Drilling a lock that could have been opened without damage.
• Replacing a whole multipoint mechanism when only the cylinder or gearbox had failed.
• Fitting cheap cylinders at premium prices.
• Demanding cash only, providing no invoice, and showing no company name or address.
• Arriving with no ID in an unmarked vehicle.

Under the Consumer Rights Act 2015, a service must be carried out with reasonable care and skill, at a reasonable price if none was agreed, and within a reasonable time. You have a right to have poor work put right or get your money back. Under the Consumer Contracts Regulations 2013, there is normally a 14-day cancellation period for work arranged at home or by phone. This does not apply where you specifically asked for a visit for urgent repairs, but any extra work sold during that visit is not covered by the exception.

If you are simply upgrading your locks to meet insurance standards, or you have moved into a new house where nobody knows who holds keys, the job can wait until the daytime rate applies. If you are locked out on the doorstep in the dark, or a break-in has left you with a door that will not lock at night, it is an emergency and you will have to pay the higher out of hours price.

Common questions

Does fitting a good lock guarantee my insurance covers me?

No. Insurers can set minimum lock standards for cover, but a lock does not guarantee a payout. The policy wording dictates the terms, and you must still use the locks properly to keep the cover valid.

Will my claim be rejected if I forget to lock the door?

It can be. Some insurers will not pay a claim if the house was not properly locked up, and an insurer is not obliged to pay out if the policy conditions were not met. Your policy wording sets the rule.

Are window lock replacements covered if my keys are stolen?

Which? found that almost all policies cover external door lock replacement after key theft, but that 63 per cent do not cover window locks. Check your own policy wording.

Is a night latch enough to secure a timber front door?

Generally, no. A night latch, often called a Yale lock, should not be the only lock on an external door.

Next steps

• Check your home insurance policy documents to find the minimum security requirements for your property.
• Look at your timber door locks for the BSI Kitemark or a BS3621 stamp on the faceplate.
• Ask your locksmith or insurer whether the lock on your uPVC or composite door meets the standard for your door.
• Check that all ground floor and accessible windows have key operated locks.
• Speak to your insurer to get written agreement if your doors have non-standard locks.
• Ask a local locksmith to quote for upgrades, ensuring they state the security standard of the new parts.

Keeping your home secure and your insurance valid gives you peace of mind, so if your locks fall short, you can find a locksmith near you to bring them up to standard.