The maximum penalty for an adult carrying a knife is 4 years in prison and an unlimited fine. You will get a prison sentence if you are convicted of carrying a knife more than once.
Basic laws on knives
It is illegal to:
sell a knife to anyone under 18, unless it has a folding blade 3 inches long (7.62 cm) or less
carry a knife in public without good reason, unless it has a folding blade with a cutting edge 3 inches long or less
carry, buy or sell any type of banned knife
use any knife in a threatening way (even a legal knife)
Lock knives
Lock knives are not classed as folding knives and are illegal to carry in public without good reason. Lock knives:
have blades that can be locked and refolded only by pressing a button
can include multi-tool knives - tools that also contain other devices such as a screwdriver or can opener
Banned knives and weapons
It is illegal to bring into the UK, sell, hire, lend or give anyone the following:
butterfly knives (also known as ‘balisongs’) - a blade hidden inside a handle that splits in the middle
disguised knives - a blade or sharp point hidden inside what looks like everyday objects such as a buckle, phone, brush or lipstick
flick knives (also known as ‘switchblades’ or ‘automatic knives’) - a blade hidden inside a handle which shoots out when a button is pressed
gravity knives
stealth knives - a knife or spike not made from metal (except when used at home, for food or a toy)
zombie knives - a knife with a cutting edge, a serrated edge and images or words suggesting it is used for violence
swords, including samurai swords - a curved blade over 50cm (with some exceptions, such as antiques and swords made to traditional methods before 1954)
sword-sticks - a hollow walking stick or cane containing a blade
push daggers
blowpipes (‘blow gun’)
telescopic truncheons - extend automatically by pressing button or spring in the handle
batons - straight, side-handled or friction-lock truncheons
hollow kubotans - a cylinder-shaped keychain holding spikes
shurikens (also known as ‘shaken’, ‘death stars’ or ‘throwing stars’)
kusari-gama - a sickle attached to a rope, cord or wire
kyoketsu-shoge - a hook-knife attached to a rope, cord or wire
kusari (or ‘manrikigusari’) - a weight attached to a rope, cord, wire
hand or foot-claws
knuckledusters
Contact your local police to check if a knife or weapon is illegal.
Good reasons for carrying a knife or weapon
Examples of good reasons to carry a knife or weapon in public can include:
taking knives you use at work to and from work
taking it to a gallery or museum to be exhibited
if it will be used for theatre, film, television, historical reenactment or religious purposes, for example the kirpan some Sikhs carry
if it will be used in a demonstration or to teach someone how to use it
A court will decide if you have got a good reason to carry a knife or a weapon if you are charged with carrying it illegally.
Additional information on selling, buying and carrying knives can be found on GOV.UK's website.