Inland air travel tax levied on fares for inland journeys and collected by authorised officers and carriers. Section 42 imposes an inland air travel tax as a percentage of the fare for every inland air journey, deeming the ordinarily payable fare to be paid where travel is concessionary or free. The tax is to be collected under rules by authorised collectors - including customs and central excise officers, designated government officers, airport authorities, or carriers notified by the Central Government - and paid to the credit of the Central Government.