Persons engaged in commercial passenger transport (other than taxi) shall be required to hold a permit to transport passengers. There are three types of permits: 1) Permits for buses: Cars carrying more than nine passengers. 2) Special cars permit: Off-road registered cars(with a tyre size of at least 780 millimetres in diameter) for 9 passengers and fewer. 3) Permit in connection with tourism: Non-modified cars registered for 9 passengers and fewer. A permit from the Icelandic Tourist Board must be available