GUIDE

Understanding Lock Grades: What Ratings Mean and Which You Need

Decoding lock security ratings—BS3621, TS007 stars, Euro standards, and what they actually mean for your home security and insurance compliance.

Lock security ratings exist to help you compare products and meet insurance requirements. But the alphabet soup of standards—BS3621, TS007, Sold Secure, Euro grades—can be confusing.

This guide explains what each rating means and which ones matter for your situation.

Why Ratings Matter

For Security

Ratings indicate tested protection against specific attacks:

  • Locks must resist picking, drilling, snapping
  • Testing by independent labs, not manufacturer claims
  • Minimum performance thresholds to achieve certification

For Insurance

Ratings are referenced in policy conditions:

  • “BS3621 mortice lock required”
  • Anti-snap cylinders recommended”
  • Non-compliant locks may affect claims

For Comparison

Without ratings, choosing the right lock is guesswork:

  • Price doesn’t equal quality
  • Appearance doesn’t indicate protection
  • Ratings provide objective benchmark
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A rating isn’t just a sticker—it’s proof that an independent lab tried to defeat the lock and failed (within the rating’s scope).

BS3621: The Mortice Lock Standard

What It Covers

BS3621 is the British Standard for high-security mortice locks. It applies to:

  • Mortice deadlocks
  • Mortice sashlocks
  • Installed in wooden doors

What’s Required

To achieve BS3621, locks must have:

RequirementPurpose
5 levers minimumKey complexity
1,000+ key differsPrevents chance matching
14mm+ bolt throwResist forcing
Hardened bolt rollerAnti-saw protection
Anti-drill featuresProtects mechanism
Anti-pick elementsResists manipulation

How to Identify

Look for:

  • BSI Kitemark on the faceplate
  • “BS3621” stamped on the lock
  • Certification number from manufacturer

If in doubt, check with manufacturer or have a locksmith verify.

What It Doesn’t Cover

BS3621 certifies the lock only, not:

  • The door it’s installed in
  • The frame and strike plate
  • How well it’s installed
  • The overall door security

TS007: The Cylinder Standard

What It Covers

TS007 is the British Standard for enhanced security cylinders. It applies to:

  • Euro profile cylinders
  • Used in uPVC and composite doors
  • Tested for attack resistance

The Star System

TS007 uses a 3-star system:

RatingWhat It Means
1-starCylinder resists some attacks but needs supporting handle
2-starHandle/hardware provides additional protection
3-starCylinder ALONE resists all defined attacks

How Stars Combine

Cylinder+ Handle= Total
1-star+ 2-star= 3-star
3-star+ 0-star= 3-star

The key: You need 3-star total protection, achieved either by:

  • A 3-star cylinder alone, OR
  • A 1-star cylinder with 2-star handle

What 3-Star Protects Against

AttackProtection
SnappingSacrificial break point or snap-resistant design
DrillingHardened pins and housing
PickingAnti-pick features
BumpingAnti-bump technology
Plug pullingSecure plug retention

Other Ratings You’ll Encounter

Sold Secure

Independent testing organisation with ratings:

  • Bronze: Basic protection
  • Silver: Enhanced protection
  • Gold: High-end protection
  • Diamond: Premium protection

Applied to various security products including locks, safes, and bike security.

PAS 24

Standard for complete door security (not just locks):

  • Tests the entire door as a unit
  • Includes frame, hinges, glazing, hardware
  • Developer/manufacturer typically certifies complete doors
  • Useful when buying new doors

Secured by Design

Police-preferred specification:

  • Recommends security-tested products
  • Works with manufacturers on standards
  • Indicates police confidence in product

European EN Standards

StandardApplies To
EN 1303Cylinder security grading
EN 12209Mechanically operated locks
EN 1627-1630Resistance to burglary

European standards may be referenced but UK insurance typically specifies BS3621 and TS007.

Matching Ratings to Door Types

Wooden Doors (Mortice Locks)

Primary standard: BS3621

Lock TypeRating to Seek
DeadlockBS3621 5-lever
SashlockBS3621 5-lever
Rim lockNot typically rated—add mortice for security

uPVC/Composite Doors (Euro Cylinders)

Primary standard: TS007 3-star

SituationRating to Seek
Cylinder upgradeTS007 3-star cylinder
New doorPAS 24 tested complete door
Handle upgradeTS007 2-star (if using 1-star cylinder)

What About Multi-Lock Doors?

Some wooden doors have both:

  • Mortice lock (BS3621)
  • Euro cylinder (TS007)

Ensure both meet appropriate standards.

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Rating confusion often comes from applying wrong standard to wrong lock type. Mortice = BS3621. Euro cylinder = TS007. Know which you have, then seek the right rating.

Insurance Requirements

Typical Policy Wording

Common requirements you’ll find:

“Fitted with a 5-lever mortice deadlock conforming to BS3621”

“Key-operated locks on all external doors”

“Anti-snap cylinders recommended for uPVC doors”

  • Required: Mandatory for coverage
  • Recommended/Expected: May affect claims
  • No mention: Check with insurer directly

Checking Compliance

  1. Find your policy documents
  2. Search for “security” or “locks” section
  3. Note specific requirements mentioned
  4. Compare to what you have installed
  5. Address any gaps

Upgrading to Meet Standards

From Non-Rated to BS3621

StepAction
1Verify door takes standard mortice
2Purchase BS3621 rated lock
3Have locksmith fit and test
4Retain certification documentation

Cost: £100-200 fitted

From Standard to TS007 3-Star

StepAction
1Measure existing cylinder
2Purchase TS007 3-star replacement
3Fit (DIY possible or professional)
4Retain certification

Cost: £60-150 fitted

Frequently Asked Questions

What's the difference between BS3621 and TS007?

BS3621 applies to mortice locks (installed inside wooden doors). TS007 applies to Euro cylinders (used in uPVC and composite doors). Different standards for different lock types.

Does my insurance require specific lock grades?

Many policies require BS3621 for wooden doors and TS007 3-star (or equivalent anti-snap cylinders) for uPVC/composite. Check your policy documents or ask your insurer directly.

Is a higher star rating always better?

For TS007, 3-star means the cylinder alone provides full protection. 1-star cylinder with 2-star handle equals 3-star total. The combination matters for installation context.

What if my lock has no visible certification mark?

It may be unrated or the mark may be obscured. If in doubt, assume it's not certified. A locksmith can often identify lock type and advise on rating.

Do I need the same grade lock on all doors?

All external doors should meet your insurance requirements. Back doors, side doors, and garage access doors need the same attention as the front door.

Are European stars different from British standards?

Somewhat. European EN standards exist but UK insurance typically references BS3621 and TS007 specifically. Ensure whatever standard is met, it satisfies your UK insurer.

How can I tell if my current lock meets BS3621?

Look for the BSI Kitemark and BS3621 marking on the faceplate. Certified locks have these stamps. If absent, the lock likely doesn't meet the standard.

Is there a rating that covers the complete door, not just the lock?

Yes—PAS 24 tests the entire door assembly including frame, hinges, glazing, and hardware as a complete unit. This is useful when specifying new doors rather than upgrading locks.

Summary

Door TypePrimary StandardWhat to Look For
WoodenBS3621Kitemark on faceplate
uPVCTS007 3-starKitemark and star rating
CompositeTS007 3-starKitemark and star rating

Ratings matter because they verify protection claims and satisfy insurance requirements. When choosing or upgrading locks, look for these certifications—they’re the difference between marketing promises and tested security.

Written by Trulox Security Experts

Trusted security experts committed to protecting what matters most.

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