Knives: The Laws on Buying and Carrying Taken from the UK gov website.
In the UK the laws about buying and carrying a knife
depend on the type of knife, your age and your
circumstances.
Basic Laws on Knives
It is illegal to:
sell a knife of any kind (including cutlery and
kitchen knives) to anyone under 18
carry a knife in public without good reason - unless
it’s a knife with a folding blade 3 inches long (7.62
cm) or less, eg a Swiss Army knife
carry, buy or sell any type of banned knife (the
list of banned knives is below)
use any knife in a threatening way (even a legal
knife, such as a Swiss Army knife)
Lock knives (knives with blades that can be locked when
unfolded) are not folding knives, and are illegal to
carry in public.
The maximum penalty for an adult carrying a knife is 4
years in prison and a fine of £5,000.
Good Reasons for Carrying a Knife
Examples of good reasons to carry a knife in public can
include:
taking knives you use at work to and from work
you’re taking knives to a gallery or museum to be
exhibited
the knife is going to be used for theatre, film,
television, historical reenactment or religious purposes
(eg the kirpan some Sikhs carry)
A court will decide if you’ve got a good reason to carry
a knife if you’re charged with carrying it illegally.
Knives That Are Illegal
There is a complete ban on the sale of some knives:
flick knives (also called ‘switchblades’ or
‘automatic knives’) - where the blade is hidden inside
the handle and shoots out when a button is pressed
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 – eg where the blade is hidden
inside a belt buckle or fake mobile phone
gravity knives
sword-sticks
samurai swords (with some exceptions, including
antiques and swords made to traditional methods before
1954)