What are BS3621 Locks? + How to tell you have British Standard Locks

Find out what BS3621 locks are, and how to tell in 2 easy steps you have BS3621 British Standard locks fitted on your doors. We will also tell you the advantages of having your door locks conform to BS3621.

What is BS3621?

BS3621 is a lock standard by British Standards Institute (BSI) for thief-resistant locks, BS-3621 locks are found on some front and back doors in the home and it’s a good way to check that your security is up to standard. This is why some insurance companies require door locks are fitted to BS 3621 British Standard.

The first question you will want to know is do my current door locks already conform to BS3621?

How to tell your locks are BS3621 – 2 Easy Steps

One way to check your front or back door locks are conforming to BS3621 is to look for the British Standard Kitemark (BSI) on the faceplate of the lock.  The faceplate of the lock is viewable when you open the door; you should also see the specific standard number e.g. BS3621 stamped on the plate.

Quick Steps on how to check lock is British Standard:

• Step 1. Look for British Standard Kitemark engraved on the lock
• Step 2. Look for British Standard number BS3621 stamped on the lock – from the above photo this is a 2007 version ‘BS3621:2007‘
• Which British Standard? – The standard of lock will be established by a number such as BS8621, BS10621 or BS3621, followed by a year, e.g BS3621:2017

What the BS3621 Kitemark looks like

If you are unsure ask a local MLA approved locksmith in your area who deals with these type of locks every day, they will also be able to upgrade your current locks to BS 3621.

About BS-3621 British Standard Locks

BS 3621 is the original lock standard and was first introduced in the 1960’s, the key facts you need to know about BS3621 locks are as follows:

• Usually found on wooden & timber doors in domestic homes, but can appear on metal doors in commercial premises.
• A key is used for opening or exiting the lock – also known as the term ‘keyed egress’.
• Cannot be opened on either side unless you have the key.
• Latest BS3621 standard version is BS 3621:2017

Not Suitable For – This standard of lock makes it unsuitable for properties with only one exit door.

Advantages of BS3621 Locks

The main benefits of having BS3621 British Standard approved locks fitted are:

• Tested against Burglary techniques such as drilling and picking
• Comply with your insurance policy – most require this standard as a bare minimum

Are BS-3621 Locks Insurance Approved?

You may see Kitemarked BS3621 locks referred to as “Insurance Approved Locks”, this just means some insurance companies require this standard of lock fitted.

BS-3621 locks are NOT actually approved by Insurance providers, the approval and certification is done by BSI (The British Standards Institute) themselves.

What type of lock are approved to BS 3621 Standard?

You will find the following types of door locks that conform to BS-3621 in your home.

Locks that can conform to BS3621:

• Mortice SashLock & Mortice DeadLock
• Euro Deadlock & Sashlock
• Rim Cylinder locks such as Night Latches & Rim Locks

BS3621 Mortice DeadLock – What you need to know

For mortice locks to conform to BS3621 the door lock must have at least 5 levers, therefore a 3 lever mortice lock CANNOT be British Standard Kitemarked to BS3621.

Confused about what door lock you have? Please read our door lock types guide here. which also includes pro’s and cons of each lock.

What does a Bs3621 lock look like?

The below photo shows what a Mortice Deadlock that is BS3621 approved locks like, note the Kitemark with the standard number below it found on the lock.

Please note that some 5 lever mortice lock DO NOT conform to BS3621, so please check before you purchase or ask a local MLA locksmith.

Confused about what door lock you have? Please read our door lock types guide here which also includes pro’s and cons of each lock.

Requirements for Locks to Meet BS 3621

For a lock to meet British Standard BS3621 it must have:

• 5 levers having at least a 1000 key differs
• Measures to prevent picking those 5 Levers
• Anti-pick qualities
• Hardplates to protect the lock from drilling
• Minimum of 20mm bolt throw into the door frame

British Standard Versions of BS3621 Locks

Over the years the BS3621 standard has been updated leading to there being different versions of BS 3621 locks available, the different years indicate the date of the standard it was approved to.

Below is a list of versions your lock could be:

• BS 3621:2017 – the latest version
• BS 3621:2007+A2:2012
• BS 3621:1998
• BS 3621:1980
• BS 3621:1963 – the first & oldest version

NOTE: The year of lock certification is not as important as actually having a BS3621 lock fitted, although it is recommended to upgrade to the latest version.

Do Home Insurer Providers require BS3621 Locks?

Some insurers may insist your locks have to meet BS3621, other insurers may not have that exact requirement, so it’s down the individual to check with their insurer regarding any standard your locks should meet.

Will a BS 3621 Lock Reduce my Insurance?

Most home insurance won’t offer cheaper insurance for BS3621 locks though as this is usually a standard requirement.  Again we recommend checking with providers to see if having your locks to meet this standard will reduce your cost of insurance.

How much does a BS3621 lock cost?

The estimated prices of British Standard BS3621 locks are as follows:

• from £36 for a Mortice DeadLock BS3621 approved
• from £38 for a Mortice Sashlock BS3621 approved
• from £95 for a Night Latch that is BS3621 approved

For estimated prices of changing and fitting locks see our locksmith price list here our guide even includes a pricelist checklist.

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Other British Standard Locks (BS8621 + BS10621)

There are two other standards you will see mentioned alongside BS3621 and that is BS8621 and BS10621, these are rarely used in domestic homes.

Used in Flats & Apartments – You will find BS8621 and BS10621 used in commercial properties & building with multiple occupants such as flats and apartments, although BS10621 is the least common.

What are BS8621 British Standard Locks?

BS8621 is a standard of lock which is used for emergency exits in the event of an emergency (IE fire), so you do not need a key to escape the building.

• BS 8621 standard was first introduced in 2004
• Can open the lock WITHOUT a key usually with a thumb turn to open
• Lockable from the outside only with a key
• Usually fitted in commercial & domestic properties, like rented accommodation, blocks of flats, multiple occupants
• Installed on external doors
• Latest standard version is BS 8621:2017

Advantages of BS621 Locks

The benefit of having a BS8621 lock is if as follows:

• Someone needs to exit a building in a hurry, there is no need to look for keys to gain exit.
• Cannot lock someone inside the building

Locks that can conform to BS8621:

• Mortice SashLock & Mortice DeadLock
• Euro Deadlock & Sashlock
• Rim Cylinder locks such as Night Latches & Rim Locks

Note: This standard of lock is not to be confused with a fire escape/panic bar.

How to tell you have a BS8621 Lock

There are two steps you can take to check your lock is a BS8621 lock:

• Step 1 – Look for the British Standard Kitemark stamped on the lock
• Step 2 – Look for the Number ‘BS8621’ engraved on the lock, followed by the version year e.g BS8621:2017

Versions of BS8621 Locks

Below are all the available versions of BS 8621 Kitemarked locks:

• BS 8621:2017 – the latest version
• BS 8621:2007+A2:2012
• BS 8621:2004 – the first & oldest version

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What are BS10621 British Standard Locks?

BS10621 is a mixture of keyed and keyless egress (dual mode ) and one of the least popular British standard of lock.

• BS10621 standard was first introduced in 2007
• Has the same test criteria as BS3621 and BS8621
• Rarely used
• Has the function of BS3621 and BS8621
• Can ONLY be locked from outside with a key
• Usually fitted in commercial & domestic properties, like rented accommodation, blocks of flats, multiple occupants
• Latest standard version is BS 10621:2017

Warning: BS10621 locks should not be used in single exit dwellings because of the entrapment possibilities

Locks that can conform to BS10621:

• Mortice SashLock & Mortice DeadLock
• Euro Deadlock & Sashlock
• Rim Cylinder locks such as Night Latches & Rim Locks

How to tell you have a BS10621 Lock

The two simple steps to check your lock is a BS10621 lock are:

• Step 1 – Look for the British Standard Kitemark stamped on the lock
• Step 2 – Look for the Number ‘BS10621’ engraved on the lock, followed by the version year e.g BS10621:2017

Versions of BS10621 Locks

Below are all the available versions of BS 10621 Kitemarked locks:

• BS 10621:2017 – the latest version
• BS 10621:2007+A2:2012 – the first & oldest version

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Summary on British Standard BS3621 Locks

To check your current locks are approved to BS3621 you should look for:

1. 1. British Standard Kitemark engraved on the faceplate of lock
2. 2. Lock standard number engraved on the faceplate of lock

Also, don’t forget, a Mortice lock must have at LEAST 5 levers to conform to BS3621.

If you are looking to upgrade your existing door locks to BS-3621, you should contact a local locksmith who will be to advise.

Prices – See our estimated prices of BS3621 approved locks our price guide even has a checklist of questions to ask the locksmith.

Related Reading

• Rim Cylinder Locks – Find out the most secure Rim cylinder
• Night Latch Guide – A simple guide + most secure Nightlatch to use
• Types of Door Locks – Identify what door lock you have plus the pros/cons of each lock