If you're replacing the lock on your uPVC or composite door, you've probably come across the terms 1 Star and 3 Star. Both are designed to improve security, but they offer different levels of protection and are intended to be used in different ways.

Choosing the right option depends on your existing door furniture and the level of security you want.

What Is a 1 Star Lock?

A 1 Star cylinder has been tested to provide resistance against common methods of attack, including lock snapping.

However, it is designed to be used alongside a TS007 2 Star security handle.

Together, they provide the equivalent of a 3 Star security rating.

To understand how these ratings work, read Understanding Door Lock Security Standards: TS007, Secured by Design and Insurance Requirements Explained.

A 1 Star cylinder is often a good choice if:

• Your door already has TS007 2 Star security handles.
• You're replacing an older lock cylinder.
• Your existing security handles are in good condition.

What Is a 3 Star Lock?

A 3 Star cylinder provides its own high level of protection without relying on a security handle.

These cylinders incorporate additional security features to help resist:

• Lock snapping
• Drilling
• Picking
• Bumping

For a complete explanation of euro cylinders and their security features, see The Complete Guide to Euro Cylinder Door Locks.

They are often chosen when:

• Standard door handles are fitted.
• The handles don't provide cylinder protection.
• The homeowner wants maximum protection from the cylinder alone.

Which Is More Secure?

When correctly installed:

• A 1 Star cylinder with a TS007 2 Star security handle provides the same overall 3 Star level of protection.
• A 3 Star cylinder provides that protection on its own.

Neither option is automatically "better"—it depends on the hardware already fitted to your door.

If you'd like to compare security ratings in more detail, read How to Compare Lock Specifications.

Secured by design and Sold secure approved.

When a 1 Star Lock Makes Sense

A 1 Star cylinder is usually the most cost-effective choice if your door already has quality TS007 2 Star security handles.

Replacing only the cylinder can improve security without replacing perfectly good handles.

When a 3 Star Lock Is the Better Option

A 3 Star cylinder is often the better choice if:

• Your door has standard handles.
• Your handles don't shield the cylinder.
• You don't want to replace the handles.
• You're looking for a simple security upgrade.

It provides high-security protection in a single component.

Don't Forget Door Alignment

Even the best lock won't perform properly if the door is out of alignment.

A dropped door can cause:

• A stiff key
• Difficulty lifting the handle
• Extra strain on the lock
• Premature wear

If your door is difficult to lock, correcting the alignment is just as important as choosing the right cylinder.

Security Is More Than Just the Lock

Your front door's security depends on several components working together, including:

• A quality lock cylinder
• Secure door handles
• A correctly aligned door
• A well-maintained multipoint locking mechanism
• Strong hinges and keeps

Upgrading only one component may not solve every security issue.

To learn more about recognised security standards, see A–Z of Door & Lock Security Standards.

Get the Right Combination

There isn't a single answer that suits every door. If you already have TS007 2 Star security handles, fitting a quality 1 Star cylinder can provide excellent protection. If your door has standard handles, a 3 Star cylinder is often the simplest and most effective upgrade.

Choosing the correct lock for your existing door hardware helps ensure you get the best balance of security, reliability, and value.

For advice on improving the overall security of your home, read The Complete Guide to Upgrading Your Door Locks for Better Home Security.