You can be stopped, fined or arrested by police if you’re under 18 and drinking alcohol in public.
If you’re under 18, it’s against the law:
for someone to sell you alcohol
to buy or try to buy alcohol
for an adult to buy or try to buy alcohol for you
to drink alcohol in licensed premises (such as a pub or restaurant)
However, if you’re 16 or 17 and accompanied by an adult, you can drink (but not buy) beer, wine or cider with a meal.
If you’re 16 or under, you may be able to go to a pub (or premises primarily used to sell alcohol) if you’re accompanied by an adult. However, this isn’t always the case. It can also depend on the specific conditions for that premises.
It’s illegal to give alcohol to children under 5.