Locks & Security Guide

Aged Brass 2½" 5 Lever BS Sash Lock, from our current range.

Locks are the part of a door's hardware that most people think about last and need most when something goes wrong. The right choice depends on the door itself (timber, uPVC or composite), whether it needs to meet insurance requirements, and how the door is used day to day. This guide covers the main lock and cylinder types you will come across.

What's included in locks & security

• Mortice Locks – locks fitted into a pocket cut in the door itself, common on timber doors and often specified for insurance purposes
• Sashlocks – a mortice lock combined with a latch, so the door can be closed without a key and locked separately
• Deadlocks – a mortice lock with no handle-operated latch, locking and unlocking only by key
• Euro Cylinders – the cylinder mechanism used in uPVC and composite doors, sized to the door and rated to different security grades
• Thumbturn Cylinders – euro cylinders with a turn knob on the inside, allowing quick exit without a key while still requiring one from outside
• Rim Locks and Night Latches – surface-mounted locks fitted to the face of a door, often used as a secondary lock alongside a mortice lock
• Multi-point Locks – locking systems used on uPVC, composite and some timber doors that engage several points down the frame at once
• Bathroom Locks and Privacy Turns – simple internal locking for bathrooms and WCs, usually operated by a turn and release button rather than a key
• Security Escutcheons – reinforced cover plates fitted around a cylinder or keyhole to resist drilling and picking attempts, covered in more detail in our Escutcheons guide
• Window Locks – locking handles and stays fitted to windows, often specified alongside door locks to meet insurance requirements
• Smart Locks – electronic and app or keypad-operated locks, increasingly specified on new build and rental properties
• Keyed Alike Locks – sets of locks cut to the same key, useful where several doors need to be opened by the same key

We are adding a dedicated guide to each lock type individually. Browse our current range in Locks & Latches and Security & Protection.

Frequently asked questions

What's the difference between a sashlock and a deadlock?

A sashlock includes a spring latch operated by a handle, so the door can close and hold shut without being locked. A deadlock has no latch and only locks or unlocks by key, so the door must be pulled shut and locked separately.

Do I need British Standard locks for insurance?

Many UK home insurance policies require BS3621 (or equivalent) locks on external doors. If you are unsure what your policy requires, it is worth checking before you buy, and our team can point you to compliant products.

What size euro cylinder do I need?

Euro cylinders are measured from the centre of the fixing screw to each end, and need to be sized to your specific door thickness. We can help you measure this correctly – see our Contact Us page.

Explore the other guides: Door Furniture, Hinges & Door Control, Cabinet & Furniture Hardware, Window Furniture and Hardware Finishes.