(1) Where an airport service charge, due and payable under regulation 3 remains unpaid by any traveller, the full amount of such charge shall be due and payable by, and recoverable from the carrier of that traveller.
(2) Where under subregulation (1) a sum of money due and payable in respect of the airport service charge is recoverable from more than one person, then the liability of such persons to pay that sum is joint and several.
(3) Any sum due and payable under this regulation may be recovered as a debt due to the Authority in civil proceedings.