Lock Replacement
Swapping a worn or outdated lock only works if the new one is measured to fit — the euro cylinder to length, the mortice case to the backset, the gearbox to the door. Knightsbridge Locksmiths replaces euro cylinders, mortice locks and uPVC gearboxes across Knightsbridge and London, sized on the door rather than guessed on site, and upgraded to a stronger standard where that helps.
When a Lock Is Due for Replacement
Not every tired lock needs replacing, but some are past a service — worn beyond repair, below the security you need, or simply the wrong spec for the door. Describe what you've got, and we'll measure the right replacement.
Worn Beyond Repair
A cylinder that's loose or a mortice that's failing can't always be serviced back. Replacing the part restores a clean, secure lock.
Below the Grade You Need
Basic builder-grade locks rarely meet insurer wording. Swapping in a BS3621 mortice or a 3-star cylinder brings the door up to standard.
The Wrong Size Was Fitted
A cylinder left proud of the door, or a case that never sat right, is a weak point. We measure and replace it so it fits flush and locks cleanly.
One Team to Replace Any Lock Correctly
Euro cylinders, mortice cases, rim latches and uPVC gearboxes — whatever needs swapping gets measured, supplied and replaced by the same engineer, priced before we travel and itemised on the invoice after.
Measured, Matched and Upgraded Where It Counts
A replacement that isn't measured is a callback waiting to happen — a cylinder too long invites snapping, a case too short won't seat. We measure the door first, then fit the correct part, taking the chance to upgrade the grade while we're there.
Sized on the door
Cylinder length, backset and case depth measured before anything is ordered or cut.
Anti-snap as standard
Where we swap a euro cylinder, a TS007 3-star or Sold Secure barrel goes in.
BS3621 where insurers ask
Five-lever mortice deadlocks fitted to meet common policy wording.
Keys handed over clean
A full set of keys for the new lock, with the old cylinder removed from use.
Getting the Replacement Right First Time
Measured, not guessed
The part sized against your actual door, so it fits flush and locks on the first turn.
Priced before we travel
Describe the lock and the quote you're given holds all the way to the invoice.
Upgrade while you're at it
A swap is the natural moment to move up to anti-snap or BS3621 at little extra cost.
Local to SW1, SW3 and SW7
Based on Montpelier Street, we're quick to reach across Knightsbridge and nearby.
How a Lock Replacement Goes
- Tell us the lock
Cylinder, mortice or uPVC gearbox, and what's prompting the swap — wear, security or a poor fit.
- Measured on site
On arrival we size the part to the door before recommending the replacement.
- Priced up front
Supply and replacement quoted before we start, with nothing added after.
- Swapped and tested
Fitted, cycled through and handed over with a full set of keys.
Lock Replacement, Neighbourhood by Neighbourhood
Locks reach the end of their life for different reasons across Central London — here's what our replacement work tends to involve in four of the areas we're called to most.
Lock Replacement Knightsbridge (SW7)
Mansion flats around Grosvenor Crescent often still run the euro cylinder the developer fitted years ago, now loose and easy to snap. We measure and swap it for a 3-star barrel that sits flush.
Lock Replacement Chelsea & Belgravia (SW3 / SW1X)
Shopfront mortice locks off Royal Hospital Road wear with heavy use and eventually stop throwing fully. Replacing the case with a like-for-like or upgraded lock keeps a trading door secure.
Lock Replacement South Kensington (SW7)
Period front doors around Emperor's Gate sometimes carry a mortice case decades old and past serviceable. A measured replacement restores security without altering the original door.
Lock Replacement Pimlico & Belgravia (SW1P / SW1E)
Terraced houses around Warwick Way often have a uPVC back door whose gearbox has failed rather than its cylinder. Measuring and replacing the correct multipoint mechanism gets it locking again.
Where We Replace Locks
Based at 4 Montpelier Street in SW7, we replace locks across Knightsbridge, Belgravia, South Kensington and Chelsea, with wider cover through the SW1 postcodes and central London. A single worn cylinder or a full set of tired locks, the callout works the same.
Knightsbridge & Belgravia
- Grosvenor Crescent
- Wilton Row
- Groom Place
- Chapel Street
- Headfort Place
South Kensington
- Emperor's Gate
- Grenville Place
- Ashburn Place
- Courtfield Road
Chelsea & Brompton
- Tedworth Square
- St Leonard's Terrace
- Tite Street
- Royal Hospital Road
Home or business, the routine holds: measure the part to the door, fit the correct replacement, and leave the lock turning cleanly on a fresh set of keys.
FAQs — Lock Replacement
How do I know if a lock needs replacing rather than repairing?
If a lock is loose, worn through or below the grade you need, replacement is usually the answer. Where it's simply stiff or misaligned, a service often fixes it — and we'll tell you which on site.
Do you measure the lock before replacing it?
Always. Cylinder length, backset and case size are measured on the door first, so the replacement fits flush rather than proud or loose.
Can you upgrade the lock while replacing it?
Yes, and a swap is the ideal moment. Moving up to a TS007 3-star cylinder or a BS3621 mortice adds real security for little extra.
Will I get new keys with a replacement?
Every replacement comes with its own full set of keys, and the old cylinder is taken out of use.
Can you replace a uPVC door lock?
We can. Both the euro cylinder and the multipoint gearbox are measured and replaced with the correct parts for your door.
How quickly can you come out?
Same-day visits are usually available from our Knightsbridge base for most SW1, SW3 and SW7 addresses. Call or WhatsApp to check the next slot.