It is illegal to smoke in a car (or other vehicle) with anyone under 18. The law changed on 1 October 2015, to protect children and young people from the dangers of secondhand smoke.
Both the driver and the smoker could be fined £50. The law applies to every driver in England and Wales, including those aged 17 and those with a provisional driving licence.
The law applies:
to any private vehicle that is enclosed wholly or partly by a roof
when people have the windows or sunroof open, or the air conditioning on
when someone sits smoking in the open doorway of a vehicle
The law does not apply to:
a driver who is 17 years old if they are on their own in the car
a convertible car with the roof completely down
Every time a child breathes in secondhand smoke, they breathe in thousands of chemicals. This puts them at risk of serious conditions including meningitis, cancer, bronchitis and pneumonia. It can also make asthma worse.