Northern Ireland today introduce a law making it illegal to sell cigarettes or other tobacco products to people aged under 18.
England, Wales and Scotland followed last October, Northern Ireland joins in after the Assembly passed the required legislation at the end of June, just before heading off for the summer recess. The Republic introduced the under 18 rule in 2004.
The change in the law is part of the drive by Minister for Health Michael McGimpsey to reduce the level of smoking amongst children and young people.
Stressing the importance of the change the minister said: "Tobacco is known to be the leading cause of preventable death in Northern Ireland.
"The cost to our society is huge and I believe raising the age of sale will help discourage children and young people from taking up this life threatening habit."
A recent study showed that some nine per cent of the 11-16 age group are smokers in Northern Ireland - a figure which has reduced from 13.5 per cent as the anti-smoking message gradually gets through.
While it is illegal to sell tobacco to the under 18s, it is not illegal for them to smoke.
Mr McGimpsey has also extended to Northern Ireland a Department of Health consultation seeking views on the future of tobacco controls, including those likely to impact on children's smoking such as advertising at point of sale and access to tobacco vending machines.
The consultation ends on September 8th.