Most electric scooters are described as mopeds within UK law. They are restricted to the 30mph limit. If you have a full motorcycle licence they can be unrestricted and have higher speeds

A provisional license, full motorcycle or car license is needed to operate a moped. An additional Compulsory Basic Training certificate is also required to ride a moped on public roads, except for anyone who obtained their full car driving licence or motorcycle license before 1 February 2001. A provisional moped licence may be obtained at the age of 16, whereas standard car and motorcycles are only available at the age of 17. Provisional licenses require learner plates and expire after two years if the license holder has not upgraded their license. Mopeds are subject to all of the same traffic laws as other vehicles. All motorised cycles/motorcycles/mopeds under 50 cc are excluded from using UK motorways.