Mortice Locks – How Do They Work?

At Locksmith Romsey, we’re often asked: What are mortice locks and how do they work? These locks have been a trusted option for decades, especially on timber doors in homes across Romsey.

Let’s break down what makes mortice locks so secure and reliable—and why they remain popular today.

What Is a Mortice Lock?

A mortice lock fits inside a slot (or mortice) cut into the edge of a door. This makes it different from surface-mounted locks, which sit on the door’s exterior.

You’ll often find 5-lever mortice deadlocks on older wooden doors in Romsey. These locks offer solid protection and are harder to force open than many modern alternatives.

Two Main Types of Mortice Locks

There are two common types:

• Sashlocks – These include both a latch (operated by a handle) and a deadbolt (operated by a key).

• Deadlocks – These only have a key-operated bolt, usually installed as a secondary lock for extra security.

How Does a Mortice Lock Work?

The key lifts a series of levers inside the lock body. Each lever must reach the correct height for the bolt to move.

More levers usually mean better security. A 5-lever mortice lock is much harder to pick than a 3-lever version. That’s why 5-lever locks are often required by home insurance providers.

Why Choose a Mortice Lock in Romsey?

We recommend mortice locks for several reasons:

• Strong and reliable – Their solid internal mechanisms stand up to wear and forced entry.

• Perfect for timber doors – Many Romsey homes still use wooden external doors.

• Insurance approved – A British Standard BS3621 mortice lock meets most insurance requirements.

When to Repair or Replace a Mortice Lock

If your key sticks, turns roughly, or the lock feels loose, don’t ignore it. These are early signs of wear. Acting early can save you money and avoid being locked out.

At Locksmith Romsey, we repair and replace mortice locks quickly. We carry BS3621-compliant locks and can usually complete the job on our first visit.

Trusted Local Mortice Lock Specialists

We’re proud to serve Romsey and nearby areas like North Baddesley, Braishfield, and Timsbury. Our locksmiths offer:

• No call-out fees

• Transparent pricing

• Same-day service wherever possible

Call Locksmith Romsey Today

If you need a mortice lock repaired, replaced, or upgraded, we’re just a phone call away.

Call 01794 743033 or visit www.locksmithromsey.co.uk to book a trusted local locksmith.