Walk into any hardware shop or browse any locksmith’s website and you’ll quickly encounter a bewildering array of lock grades, ratings, and standards. BS3621, TS007, Sold Secure Diamond — what do they all mean, and which one do you actually need? In this guide, we cut through the jargon and explain lock grades and British Standards in plain English, so you can make an informed decision about the security of your home.
Why Do Lock Standards Matter?
Lock standards exist to provide a consistent, independently verified measure of a lock’s security performance, not just its resistance to attack. Without standards, it would be impossible to compare different door locks from different manufacturers, and British Standards help do exactly that; lock grades in the UK are set by the British Standards Institution, so claims such as “high security” can be judged against a recognised benchmark. For homeowners, standards also matter because insurance requirements are often specific, and most UK home insurers look for locks that meet BS3621 or TS007 as a condition of cover.
BS3621: The Insurance Standard
BS3621 is the British Standard for thief-resistant residential door locks, including high-security mortice locks for wooden doors and other lock types used on external doors. It covers a range of lock types including mortice deadlocks, rim deadlocks, and cylinder locks. The current edition is BS 3621:2017+A1:2024, and to comply products should display the british standard kitemark on the faceplate. A lock that meets BS3621 has been independently tested and rigorously tested to resist a defined set of attack methods, including picking, drilling, and forced entry, with a three-minute attack test; it also requires key operation from both sides and a minimum of 1000 key combinations. Many policies require at least one BS3621-compliant lock on each external door, and a typical insurance policy may require them on all external doors for insurance compliance. Using mismatched lock grades across different door types can also create problems and may lead to rejected claims.
TS007: The Cylinder Locks Rating
TS007 is a technical specification for euro cylinders fitted to upvc or composite doors, whereas BS3621 is generally used for timber doors, and that’s the key difference between the two standards. It is a three-star rating system: 1-star options offer basic security and are often paired with security handles, while 3-star cylinders provide enhanced security. A TS007 3-Star rating indicates that the cylinder has passed rigorous testing for resistance to snapping, picking, drilling, and bumping; some anti snap cylinders also use sacrificial sections to improve attack resistance and forced-entry protection. This is the rating recommended by the police’s Secured by Design initiative and by most insurers. BS EN 1303 is another european standard for cylinders, rating them for durability, corrosion, and key security.
Sold Secure: The Independent Rating
Sold Secure is an independent testing body that awards Bronze, Silver, and Gold ratings to security products. For locks, a Sold Secure Gold rating is the highest level and indicates a product that has withstood sustained attack testing. Sold Secure ratings are widely recognised by insurers and are a reliable indicator of quality.
Which Lock Grades Standard Do You Need?
For most homes, choosing the right lock grade for the front door and back doors matters because burglars often target the weakest lock, and consistent lock grades across external doors strengthen your home’s security. For most UK homes, the most significant residential security standards are TS007 3-Star rated anti-snap cylinders on UPVC and composite doors and a BS3621-compliant mortice deadlock on timber doors; high-security locks like these resist snapping, drilling, and picking, and some policies may require BS3621 on all external doors depending on the insurance standards.
PAS24 is a specification for door assemblies in the UK, and for new-build properties it tests the entire door assembly with manual and mechanical checks, including the frame, hinges, lock body, and other hardware, to confirm enhanced security performance requirements for the entire door.
If you’re unsure whether your current locks meet these security standards, KMG Locksmiths can carry out a free assessment and recommend the most appropriate lock upgrades for your property. Where keyless exit is needed, BS8621 can be a practical upgrade without losing secure key entry from outside. We supply and fit locks from leading manufacturers across Skelmersdale, Wigan, St Helens, and the wider North West, ensuring they are installed correctly so they function as intended, align precisely with the frame, and are less likely to be compromised after a break in or if you’ve recently moved. We also recommend regular maintenance, with annual cleaning and lubrication, to preserve smooth operation and maximum security for main doors, window locks, and other external locks. Get in touch today for a free quote.