New Homeowner's Lock-Change Checklist (UK)

Picking up the keys to a new home is exciting — but those keys have a history. You have no way of knowing how many copies are out there, who the previous owners gave spares to, or which builder, cleaner or estate agent still has access. Changing the locks should be near the top of your moving-in to-do list. Here is a practical UK checklist to work through.

1. Start with the front and back doors

Your most important locks are the external doors. The type of work needed depends on the door:

• Timber doors usually have a mortice deadlock and/or a nightlatch. For insurance, the deadlock should be a 5-lever BS3621 unit (look for the British Standard kitemark stamped on the faceplate).
• uPVC and composite doors use a multipoint locking mechanism operated by a Euro cylinder. You often do not need to replace the whole mechanism — swapping the cylinder for an anti-snap, TS007 3-star or SS312 Diamond rated one is enough to take control and boost security.

2. Don't forget the secondary doors

Side gates, garage doors, conservatory and patio doors are common weak points. Patio doors should have proper key-operated locks, and any door that leads into the house deserves the same attention as the front.

3. Check the windows

Many insurers expect key-operated window locks on accessible windows (ground floor and anything reachable from a flat roof or extension). Test every catch and make sure you have the keys.

4. Decide: change or rekey?

You have two routes to removing the previous occupants' access:

1. Replace the cylinder or lock entirely — the simplest option for uPVC doors and a chance to upgrade to a higher security standard at the same time.
2. Rekey — the lock body stays but the internal pins are changed so old keys no longer work. Useful when the existing hardware is already good quality.

Our overview of lock replacement and installation explains which approach suits each door type and how upgrades are fitted.

5. Bring everything up to insurance standard

Most home insurance policies set minimum lock requirements, and a claim can be refused if your locks fall short. As a rule of thumb, final exit doors should meet BS3621 (or BS8621 for a thumb-turn version where escape matters), and accessible windows should have key locks. Moving in is the ideal moment to fix any gaps. If you are renting the property out, our landlord locksmith guidance covers your obligations between tenancies.

6. Set up sensible key management

• Decide who genuinely needs a key and cut only as many as you need.
• Keep a record of who holds each key.
• Avoid leaving spares in obvious hiding spots — under the mat and in plant pots are the first places anyone checks.
• Consider a key safe with a strong code if tradespeople or carers need occasional access.

Your move-in security checklist at a glance

• Change or rekey all external door locks.
• Upgrade uPVC cylinders to anti-snap 3-star.
• Confirm deadlocks meet BS3621.
• Fit or test key-operated window locks.
• Secure garage, side gate and patio doors.
• Cut only the keys you need and log who has them.

Working through this list in your first week means you start life in your new home knowing exactly who can get in — and that is the whole point.