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

https://lawstuff.org.uk/at-what-age-can-i/buy-and-consume/