Before you start to drive you must:
hold a valid provisional driving licence for Great Britain or Northern Ireland.
Normally for car drivers, the earliest date your provisional licence can become valid is your 17th birthday, however you can apply for your licence up to three months before your 17th birthday.
So, if you apply for your provisional licence before you are 17 you will still have to wait for your birthday before you can start your lessons or take the theory test.
Disability Living Allowance:
If you are receiving Disability Living Allowance at the higher rate your provisional licence will come into effect when you are 16, but you can apply for it within three months of your 16th birthday.
For more information and to apply for your licence, Click Driver and Vehicle Licensing Agency.(DVLA)