There are different types of motorbike licence for people of varying ages, experience and types of bike.     First, you’ll need a provisional Category A licence – this just tells the DVLA that you’re a new rider. You’ll then need to take a theory and practical test for each licence.
If you’re 16 or over – AM Moped licence: This means you can ride a motorbike, moped or scooter up to 50cc.
If you’re 17 or over – A1 Motorcycle licence: This means you can ride a motorbike or scooter up to 125cc.
If you’re 19 or over – A2 Motorcycle licence: This means you can ride a motorbike up to 500cc engine size.
If you’re 21 or over – Unrestricted A Motorcycle licence: This means you can ride any size and power of motorcycle or scooter.
If you’re 17 or over, you can ride a bike up to 125cc after you complete your Compulsory Basic Training (CBT), without the need to take your full licence. That is, as long as you have L-plates on the bike.     This can mean a slightly more expensive insurance premium though, because as long as you’re on a provisional licence, you’ll be classed as a learner rider.