Not all learner drivers need to take the theory test.

If a learner driver holds a full driving license and want to upgrade within a vehicle category you will not normally need to take the theory test, for example if you want to upgrade from category B (car) to B+E (car with trailer).

However you must take the theory test if you want a license for a new category of vehicle, for example if you have a motorcycle license and you you want a car license you will have to take a theory test.