What is and isn't legal
the maximum penalty for carrying a knife is four years in prison and a fine of £5000 it is illegal for any shop to sell a knife of any kind (including cutlery and kitchen knives) to anyone under the age of 18
it is generally an offence to carry a knife in public without good reason or lawful authority (for example, a good reason is a chef on the way to work carrying their own knives)
the maximum penalty for an adult carrying a knife is four years in prison and a fine of £5000
knives where the blade folds into the handle, like a Swiss Army Knife, aren't illegal as long as the blade is shorter than three inches (7.62 cms)
Offensive weapons
If a knife is used in a threatening way (even a legal knife, such as a Swiss Army knife), it is regarded as an 'offensive weapon' by the law. This is also the case with things like screwdrivers - once used in a threatening manner, they are treated as offensive weapons. It is an offence to carry an offensive weapon in a public place, if you don't have a reasonable excuse. This means that carrying something that could be viewed as an offensive weapon, and then using it in a threatening way, could mean that you are prosecuted. The penalty is up to four years' imprisonment and/or a fine.
There is a complete ban on the sale of certain types of knives categorised as offensive weapons, regardless of their use, these include:
flick knives - knives where the blade is hidden inside the handle and shoots out when a button is pressed; these are also called 'switchblades' or 'automatic knives'
butterfly knives - where the blade is hidden inside a handle that splits in two around it, like wings; the handles swing around the blade to open or close it
disguised knives - where the blade is hidden inside something like a belt buckle or fake mobile phone
The police's 'Stop and Search' powers
Police officers may stop you, and have the right to search any person or vehicle, if they suspect you of an offence - including carrying an offensive weapon. Weapons regarded as offensive include, but are not limited to, the following:
flick knives
gravity knives
knuckle-dusters
sword-sticks
samurai swords
hand-claws
foot-claws
belt-buckle knives
push daggers
butterfly knives
blow-pipes or guns
kubotan (cylindrical container, holding spikes)
shuriken (also known as 'death stars' or 'throwing stars')
telescopic truncheons (automatically extending)
kusari-gama (sickle attached to a rope, cord or wire)
kyoketsu-shoge (hook-knife attached to a rope, cord or wire)
kusari (weight attached to a rope, cord or wire)
disguised knives (for example, lipstick knives)
stealth knives
straight, side-handled or friction-lock truncheons