Looking at driving licenses, the minimum age for using a ride-on mower is 16. It comes under Category K: “A mowing machine is a specialist ride-on grass-cutting vehicle with permanent cutting equipment. You must be 16 to use this type of vehicle”. Unfortunately, even if it was road registered you still wouldn’t be able to use it on the road, and then there is also the issue of insurance.
Also, mobility scooters have different registration categories and a mower could never be classed as one.
Having looked at the government websites, it looks like there is no legal way around the law that would allow the use of a ride-on mower on the road by anyone under 16.
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