Transport for London (TfL) has announced that all privately-owned electric scooters and unicycles, including those that can be folded or carried, will be banned on London’s transport network from Monday 13 December.

This results from safety concerns about these items following recent fires on TfL premises & services. Customers in possession of such devices will not be permitted to enter any premises on TfL’s network or travel on any of its services.
tfl.gov.uk