Yes. You cannot know how many copies of your keys exist or who holds them – previous owners, tenants, family, agents or tradespeople. Replacing the relevant locks or cylinders when you move in means the old keys no longer work.
Moving into a new home? You can book AHLP in advance at no cost. There is no charge for making the advance booking or if your plans change. The locksmith work itself is chargeable; ask for a quote for the locks or cylinders you need.
It is the job people mean to get round to and often never do. Here is what needs checking when you move, what a lock or cylinder replacement involves, and how to plan it.
Why it matters more than people think
When you collect the keys to a new home, you are being handed the copies the seller knows about. What you cannot be handed is the unknown: the spare set with a former partner, the neighbour who watered the plants three years ago, the cleaner, the builder, the letting agent's tagged copy that was never collected back in. None of these people need to be dishonest for it to matter – keys get lost, borrowed and copied, and you have no record of any of it.
The Master Locksmiths Association's own guidance is direct: if you have recently moved into a new home, whether a new build or an older property, you should look at changing the locks. Police crime prevention advice makes the same point about doors being the first thing a thief assesses. This is not scaremongering; it is a one-off job that removes a risk you cannot otherwise quantify.
What actually needs doing
Walk the property and list every way in:
Front and back doors. On suitable uPVC and composite doors, the euro cylinder can be replaced without replacing the whole handle or mechanism. On wooden doors the lock may be a mortice lock or a nightlatch. A locksmith can identify what is fitted and what needs replacing.
New builds are not exempt. Site keys pass through developers, site managers, subcontractors and sales teams. Some developers hand over locks that were used throughout construction. A cylinder change is still the sensible first job.
The forgotten doors. Garages, side gates, sheds, French doors, patio doors and upstairs windows with key locks. Anything the previous owner used, someone else may still have a key for.
Replace the lock or the cylinder?
AHLP replaces locks or cylinders; it does not re-key existing locks. If the locking mechanism and other hardware are suitable and working correctly, replacing the cylinder may be enough to stop the old keys working. Worn, damaged or unsuitable locks may need a fuller replacement. The right option depends on the door, its hardware and your insurer's requirements. Check your policy's security conditions and ask your insurer if anything is unclear. Different door and lock types use different standards; BS3621 and TS007 are not interchangeable or universal policy requirements.
What it typically costs
The price depends on the lock, door, parts required and time of attendance. Ask for a written total and a breakdown before anyone travels, and agree the work before it starts. Making an advance booking is free and there is no charge if your moving plans change. The locksmith work and any replacement parts are chargeable.
When to book it
Book for moving week, ideally completion day or within the first few days, when you can walk the locksmith round the property. You can arrange the visit with AHLP in advance for free, and there is no charge if plans change. Ask about garage, gate and window locks while planning the work. Contact AHLP to arrange a visit and discuss the work.
Frequently asked questions
Should I change the locks on a new build house?
Yes, it is sensible to consider a lock or cylinder change. Keys may have been shared during construction. Ask the developer about the installed locks and key arrangements, then have a locksmith check what replacement is suitable.
Do I need a full lock replacement when moving home?
Not always. AHLP can assess whether replacing the cylinder is suitable or whether the complete lock needs replacing. The decision depends on the door, the condition of the hardware and your security requirements. Ask for a quote for the recommended work before it starts.
Do I need to change locks for home insurance?
Check your own policy. Security conditions vary by insurer, policy and door type, so moving home does not create one universal lock-change requirement. Ask your insurer to confirm any required lock standard or key-security condition, then give that information to your locksmith. Do not assume a particular standard guarantees cover.
How soon after moving house should I change the locks?
Ideally on completion day or within the first week. Every day before that, an unknown number of existing keys still open your home. Book the visit in advance so it is a planned, normal-hours job rather than something urgent.
Sources and checks
- Master Locksmiths Association, "Should You Change Locks On New House After Moving?" – MLA guidance recommending lock changes on moving in, new build or older property. https://www.locksmiths.co.uk/faq/should-you-change-locks-on-new-house-after-moving/
- Which? Trusted Traders, "Cost guide: locksmiths" – independent average cost figures, treated as guides since the job varies. https://trustedtraders.which.co.uk/articles/cost-guide-locksmiths/
- Essex Police, "Door security" crime prevention advice – your front door tells a thief the security level of your home. https://www.essex.police.uk/cp/crime-prevention/residential-burglary/door-security/
Sources checked 22 October 2026. Every property differs; we will always tell you which locks genuinely need changing and which are fine left alone.