CBT stands for Compulsory Basic Training. This is a course you need to take before you’re legally able to ride a motorbike or moped on the road. It’s only the first level of qualification, so you’ll still need to pass a full motorbike or moped driving test. Once you’ve completed your CBT (it’s not a test that you pass or fail), you must pass your full test within two years or you’ll have to complete the CBT again. But it allows you to legally ride a moped or up to a 125cc motorbike, as long as the power output is no more than 11kW. You can find out more on getting a motorbike licence here.