locksmiths.tradeLocal locksmiths, town by town

Service

Lock change

Changing a euro cylinder costs £105 to £175 fitted in the Master Locksmiths Association's and MyJobQuote's 2026 price guides, and a BS 3621 mortice deadlock £100 to £205 across the MLA, Checkatrade, MyJobQuote and Bark. On most uPVC and composite doors only the cylinder is changed, not the mechanism. Moving house and lost keys are the usual reasons.

Illustration: a euro cylinder lock, face on

What this covers

What it costs. An anti-snap cylinder costs from £137 fitted on the MLA's 2026 list, and Checkatrade's 2026 average is £150, against £105 to £175 for a standard euro cylinder (MLA, MyJobQuote). Full cost breakdown.

What the job covers

  • Swapping the euro cylinder on a uPVC or composite door after moving in
  • Replacing a worn mortice deadlock with a BS 3621 lock on a timber door
  • Changing a nightlatch for one with a deadlocking key
  • Changing locks between tenancies and giving the landlord a set of keys
  • Fitting new locks after keys have been lost or stolen

What is involved

Most lock changes are simpler than people expect. On a uPVC or composite door the key turns a euro cylinder, held in by a single screw through the edge of the door, so changing the lock means swapping the cylinder, not the multipoint mechanism behind it. The new cylinder has to be the right length on each side of that screw. One that stands proud of the handle by more than a few millimetres is easier to attack, so a careful locksmith measures rather than guesses, and offers an anti-snap cylinder rated TS 007 3 star or SS 312 Diamond.

On a timber door the main lock is usually a mortice deadlock set into the door, often with a nightlatch above it. Home insurers commonly ask for a 5 lever mortice deadlock to BS 3621 on final exit doors, so check your policy before choosing a cheaper lock. A nightlatch can be changed for a deadlocking one, which cannot be slipped back from outside once it is locked.

New owners rarely know who still has keys: builders, previous owners, neighbours. Changing the cylinders is the usual first job after moving in, and Land Registry data puts the busiest months for completions in June, August and March. A lock change after lost or stolen keys follows the same pattern.

Tenants should check the tenancy first. Most agreements say the landlord must agree to a lock change and be given a key. Landlords changing locks between tenancies often have every cylinder keyed alike, so one key opens the front and back doors. A careful locksmith also checks that the door closes and locks without forcing, because a new lock on a dropped door soon wears out.

Choosing someone for the job

Ask for the total before work starts, per lock: the lock itself, labour, VAT and any call-out charge. Ask which standard the new lock meets (BS 3621 for a mortice deadlock, TS 007 3 star or SS 312 Diamond for a cylinder) and ask for it on the invoice, since your insurer may want it. Ask how many keys come with each lock and whether the locks can be keyed alike. If you rent, get the landlord's agreement first. And ask which make of cylinder they fit, so you know how to order spare keys later.

Read next

Common questions

Can a tenant change the locks?

Check the tenancy first. Most say the landlord must agree to a lock change and be given a key. In an emergency, such as stolen keys, tell the landlord straight away and keep the old cylinder. A locksmith can fit a new cylinder without touching the rest of the lock.

Do I need to change the whole lock or just the barrel?

On most uPVC and composite doors, just the barrel: the euro cylinder comes out with one screw and the multipoint mechanism stays. Change the mechanism only if it is worn or broken. On a timber door the mortice deadlock is a complete lock and is changed as one.

How do I measure a euro cylinder?

Measure from the centre of the fixing screw to each end of the cylinder, which gives two figures such as 35/45. Measure the existing cylinder rather than the door, and choose a size that sits close to flush on the outside. A locksmith measures before fitting.

Should I change the locks when I move house?

It is usually worth it. You cannot know how many keys the previous owners, builders or neighbours still hold. On uPVC and composite doors changing the cylinders is quick and leaves the mechanism in place, and it is a chance to fit anti-snap cylinders.

Find a locksmith near you Describe your job

Locksmiths who take on lock change

1034 listed locksmiths say they do this work.

Specialists in lock change first

Those listing the fewest other services come first.