Yale, Mortice or Euro Cylinder? UK Lock Types Explained

If you've ever had a locksmith on the phone and they've asked 'is it a Yale, mortice or euro' and you've gone blank — this guide is for you. UK doors run a small handful of lock types, almost always in combinations. Knowing what you have makes phone calls quicker, quotes faster, and helps you spot when a lock isn't pulling its weight.

Yale rim latches sit on the inside face of the door, not in the door edge. The latch is the spring-loaded bolt that catches when you close the door. Outside, you see a small round cylinder with a keyway. Inside, you see a chunky case with a thumbturn. Yale latches are quick — they self-lock when the door closes — but they're not insurance-grade on their own. They need to be paired with a mortice deadlock for compliance.

Mortice deadlocks sit inside the body of the door — you see only the brass faceplate on the door edge and a keyway on each side. They use a deadbolt that throws into the door frame when you turn the key. The British Standard for these is BS3621 (look for the Kitemark stamped on the faceplate). Mortice deadlocks are slow to operate (you have to deliberately lock the door with a key) but they're the security workhorse of UK wooden doors — almost every insurance policy requires them.

Euro cylinders are the long horizontal lock that runs through UPVC and composite doors. The keyway is in the centre, with a cam at the back that drives the multipoint locking mechanism. Euro cylinders come in three variants: standard (vulnerable to lock snapping), 1-star (limited snap protection), and TS007 3-star (full snap protection). The 3-star is the modern minimum we recommend on every UPVC and composite door.

When you lift the handle on a UPVC or composite door, you're driving a multipoint locking mechanism — a system of hooks, deadbolts, and rollers that engage at 3-5 points along the door edge simultaneously. The mechanism is driven by the cam on the euro cylinder. Common manufacturers: Yale, ERA, GU, Maco, Winkhaus. When the central gearbox in this mechanism fails, the door won't lock at all — replacement is £125-150 fitted, far cheaper than a new door.

Wooden front door (Victorian or Edwardian terrace): Yale rim latch on top, BS3621 mortice deadlock below. Modern wooden door (post-war semi): same combination. UPVC front door (any age): euro cylinder driving a multipoint mechanism, typically with a separate Yale or hook-bolt latch in the central handle. Composite door (modern, looks like wood but is GRP): euro cylinder + multipoint, usually with a single multi-bolt mechanism. Patio sliding door: usually a hook-bolt with key cylinder, plus a foot-bolt at the bottom.

Yale rim latches are usually repairable if the spring is weak (£45-65 service). Replace if the cylinder is sloppy or the latch case is cracked. Mortice deadlocks are repairable if a lever spring has fatigued (£65-85). Replace if the body is worn or the lock isn't BS3621-compliant (£150-180). Euro cylinders are rarely worth repairing — if the keyway is sloppy or the cylinder pre-dates 2015, replace with TS007 3-star (£120-180). Multipoint gearboxes are replaceable in 30 minutes (£125-150); the door itself doesn't need to change.

Three things speed up a phone quote: door material (wood, UPVC, composite), what the lock looks like from outside (round Yale-style cylinder, long horizontal cylinder, no visible cylinder = mortice), and what's wrong (won't turn, won't open, won't lock, key broken inside, handle floppy). With those three details a locksmith can quote a fixed price and an arrival time in under 60 seconds.