High Security Door Locks – Anti-Snap Cylinders, Sashlocks & Gearboxes
Your front door lock is your first line of defence. Upgrading an old or unrated lock to a high security door lock is one of the most effective, low-cost ways to protect your home.
This collection brings together our door locks for every door type: anti-snap euro cylinders, BS3621 mortice sashlocks and deadlocks, multipoint gearboxes, keypad door locks and padlocks.
If the key turns but the door won't lock, or the handle won't lift, the problem may be the gearbox inside the door rather than the cylinder. See multipoint door locks and gearboxes.
Timber front doors
You need a mortice sashlock or deadlock rated to BS3621, the British Standard most UK insurers ask for on external wooden doors. Browse mortice locks and sashlocks.
French and patio doors
Fit a 3-star cylinder, then add a patio door security lock that locks both handles together. For inward-opening doors, sash jammers add extra locking points.
Keyless entry
A keypad door lock opens with a code instead of a key. Popular for rentals, offices and side doors.
TS007 (euro cylinders): rated 1 to 3 stars. A 3-star cylinder has been tested against snapping, bumping, drilling, picking and plug extraction, and gives the full rating on its own. Look for the Kitemark and stars on the face of the cylinder.
BS3621 (mortice locks): the British Standard for mortice deadlocks and sashlocks on timber doors.
Sold Secure Diamond: an independent forced-entry test run by the Master Locksmiths Association. The Avocet ABS and APECS cylinders carry it.
Not sure what you need? Contact us with a photo, or visit our Aintree trade counter.
For uPVC and composite doors, a TS007 3-Star anti-snap euro cylinder is the highest standard, ideally backed by Sold Secure Diamond testing. For timber doors, a BS3621 5-lever mortice deadlock or sashlock is the benchmark. If your current lock carries no rating markings, upgrading it is the single most cost-effective security improvement you can make.
Most UK insurers require BS3621-rated mortice locks on external timber doors, and key-operated multipoint locking on uPVC or composite doors. Some policies specify TS007-rated cylinders. Always check your policy wording — a burglary claim can be reduced or refused if the locks specified aren't fitted and used.
Look at the face of the cylinder around the keyhole: anti-snap cylinders carry a Kitemark with a star rating (1, 2 or 3 stars under TS007). No markings usually means no snap protection — a standard cylinder can be snapped in under a minute with basic tools, which is the most common uPVC break-in method.
Usually, yes. Swapping a euro cylinder takes around ten minutes — one retaining screw in the door edge, slide the old cylinder out, slide the new one in. Mortice locks in timber doors are a bigger job requiring chisel work, so choose a like-for-like case size to avoid it. Our team can talk you through either.
A euro cylinder is the barrel-shaped lock used in uPVC, composite and aluminium doors, driving a multipoint mechanism. A mortice lock is a complete lock case cut into the edge of a timber door, operated by a lever key. They're not interchangeable — your door type decides which you need.
Order by 2pm and we dispatch the same working day, with UK delivery in two working days for £2.99. If you're local, our Aintree trade counter in Liverpool stocks the full lock range and offers free expert advice, key cutting and same-day pickup.
