What requirements does a mini bike need to be street legal?

There is no one answer to this, it will depend on if the bike is imported, age, and type... for example if the bike is a new import, and has a ground clearnce of 30cm+, and a set height of 90cm+ then it can be registered for road use as an enduro (the DVLA may wish to inspect it, but you will only need a brake light).. if it does not meet these standards then it will have to go down the road of an SVA test.. they are tough but passable they will check everything on the bike, the best way to check is phone the SVA test centre and if you have to take it down that route then get one of these http:/www.vosa.gov.uk/vosa/motorcycleowners/importingandbuildingvehicles/vehicleapprovalpolicyandguidance.htmit also depends on what state you are in most states first require a EPA certification and since most mini bikes are off road only. that means they are not EPA certified and can't run on the road