The Provisional Licence
Everyone needs some sort of licence, otherwise you can't take to the road even under instruction.
The minimum age for a UK provisional licence is 17. You will need this before you can start taking lessons.
You cannot start to drive a car until your provisional driving licence has been accepted and in your possession. You can apply for your licence up to 2 months before your licence is due to start. But you MUST NOT drive on the road until your licence has arrived and not until the day of your 17th birthday.
If you have never held a driving licence before you will need to complete a driving licence and photocard application form D1 (available from most post offices) and send it to DVLA with the appropriate fee.
If you do not wish to send your identity documents through the post, a premium service for checking photocard applications is available at selected post office branches. Your application can be checked for accuracy and completeness and your identity documents returned to you immediately. The premium service fee is £4.00 and is in addition to the standard driving licence fee for applications sent direct to DVLA.
DSA website.