FTR carrying [some] pocket knifes is legal in England and Wales. It is a criminal offence in Scotland.
The UK consists of England, Wales, Scotland and Northern Ireland. 3 different legal systems (though England and Wales and Northern Ireland are similar).
Scotland is radically different with many things being criminal offences in Scotland but are perfectly legal in the other 3 countries, e.g. certain types of violent pornography are serious jail time in Scotland but legal elsewhere in the UK. Plus the knife thing, obviously. Children of 8 years are criminally responsible [i.e. /are/ prosecuted] in Scotland but it is older elsewhere in the UK.