I assume you are excluding pedelec tricycles which need no licence.
A motorised tricycle (no pedals) which otherwise fits the EAPC regulations requires a category Q driving licence:
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Category Q
You can drive 2-wheeled and 3-wheeled vehicles without pedals with:
- an engine size not more than 50cc if powered by an internal combustion engine
- a maximum design speed of no more than 25km/h (15.5mph)
This category also includes trial e-scooters.
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If it's faster than a 15.5 mph machine but not exceeding 28 mph, you need a category AM driving licence :
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Category AM
You can drive 2-wheeled or 3-wheeled vehicles with a maximum design speed of over 25km/h (15.5mph) but not more than 45km/h (28mph).
This category also includes light quad bikes with:
- mass in running order of not more than 425kg (not including batteries if it’s an electric vehicle)
- maximum design speed of over 25km/h (15.5mph) but not more than 45km/h (28mph)
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Above that you are into car driving licence categorisation.
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