talkmagic.co.uk

I've researched this;

A 3 inch folding blade which does not lock open is legal to carry in public except in schools and a couple of other places (probably courts and the like).

A fixed or locking blade of any length, or a folding blade (non-locking) of more than 3 inches is illegal unless you have good reason to carry it (i.e. use for work, religious or national dress, to carry out tasks whilst camping etc).

Any sprung or gravity powered blade such as a flick knife or butterfly knife is illegal to buy, as is any blade which is designed to be concealed such as belt buckle knives. Any such blades which were owned before the law was written may be kept, but no others.

It is illegal to sell any knife as a combat or fighting knife.