Wanted to mention that 16 year olds could buy cigarettes until 2007, went to check the year, found that more interestingly:
You can smoke cigarettes at any age, but you are not allowed to buy them until you are 18.
If you are caught smoking by a uniformed police officer or park keeper in a public place when under 16, he or she can take away your tobacco and cigarette papers.
s.7 Children and Young Persons Act 1933