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This article is quite technical and might not interest all Neighbourhood Alert members.  However, though the offence of 'bumping' is thankfully rare, we have a duty to alert members to the (small) risk and to give you the opportunity to upgrade your lock(s) should you wish.


Lock bumping is a technique whereby certain locks can be opened with a specially prepared "bump" key and a suitable hitting tool. Only certain locks can be bumped. Most locks that rely only on a pin tumbler mechanism can be bumped. Many cylinders in rim locks and uPVC doors have pin tumblers. Fortunately it is quite easy to protect yourself from bumping.

The easiest way to protect yourself is to use a lock that does not use a pin tumbler. Most mortise locks use levers and do not use pins on springs so are bump proof by design. Check if your mortise lock is British Standard by looking for the Kitemark:

The first step in bumping a lock is creating a bump key for that lock. To create a bump key you need a key which has the correct profile to fit into the lock i.e. it needs to be able to fit into the lock. The more popular and widely available your lock the greater the chance a bump key can be easily created. If your lock has a restricted key profile or a very uncommon profile it will be harder to create a bump key. This will offer some protection against having your lock bumped but it may still be possible to manufacture a key with the correct profile. So a restricted key profile alone may make a lock harder to bump but does not make a lock bump proof.

Many rim locks are vulnerable to bumping because they use pin tumblers.

Some locks that utilise pin tumblers also contain additional security elements such as a sidebar. These elements may significantly reduce the risk of bumping, as although the pin tumblers can be bumped the sidebar would frustrate or prevent a bumping attack.


It should  be possible to upgrade the cylinder in your lock to one that is very hard or virtually impossible to bump. Many cylinders found in door locks are fairly easy to remove and replace and can be done on a DIY basis. New cylinders/locks  should cost in the area of £25 depending on length and  should be kite marked these will be: Anti bump, anti pick, anti snap, anti drill.

uPVC Doors: Many Euro profile cylinders found on uPVC doors are vulnerable to bumping and should be upgraded. Often this cylinder is the only lock controlling all the bolts on the door so it is very important it is secure. There is a single screw on the edge of the door that retains the cylinder that needs to be removed. Then the key needs be inserted and turned a quarter turn to align the cam and the cylinder can be pulled out the door.

Rim Locks: Most rim locks have a common rim cylinder on the outside of the door that can be easily upgraded. The outside cylinder can be removed by removing the lock and undoing the two screws which hold it in place. Some rim locks also have a cylinder on the inside. These are often built into a handle and are not easily upgraded.

You should always purchase Euro profile cylinder locks the correct length so they fit flush with the door on both sides, they are available in a wide variety of lengths (up to 67)  to facilitate this.


This type of offence is thankfully rare but the information on how to use this technique is widely available to offenders, so is the equipment required.


If you don’t have the required skills to upgrade your own lock(s) we recommend you contact a reputable local locksmith (Membership of the Master Locksmiths Association is a good sign) and always get three quotes for any work.  Prices for locksmith work can vary tremendously.


Buy With Confidence is an approved trader list which includes locksmiths, plumbers, gardeners and a whole host of other businesses.


All the companies have been vetted by trading standards officers to ensure they are solvent, adequately insured and don’t have a history of ripping people off. Previous customers are also contacted to make sure they were satisfied with the work that was carried out.


The Buy With Confidence scheme is free to use. Visit website: and simply type in your postcode and the type of trader you want and it will give you a list. Or you can phone Consumer Direct on 08454 04 05 06 for your nearest traders. See link from useful contacts on the  NA site


If you are a trustworthy trader, please get in touch to find out how to join the scheme. Or if you are a satisfied customer, why not tell your trader about Buy With Confidence?

The approved trader scheme is run by trading standards officers at Nottinghamshire County and Nottingham City Councils.


For further guidance on any of the content of this article please email

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