I'm not sure if this is unique to the UK or not, but if you don't have a full licence, you can apply for a provisional; the pre-requisites being the following:

• be at least 15 years and 9 months old.
• be able to read a number plate from 20 metres away (which isn't checked or enforced until the driving test anyway).
• have been given permission to live in Great Britain (England, Scotland and Wales) for at least 185 days.
• £34

So most people have a licence in the UK, regardless of whether they can drive. Usually so we don't have to carry our passports to the pub when we turn 18. (Which also isn't unheard of here).