Input tax credit restriction limits recoverable credit on same-line transport input services when upstream tax exceeds downstream rate. Heading 9966 sets GST categories for rental and charter services of transport vehicles, distinguishing services where fuel cost is included and imposing a restriction that input tax credit on input services in the same line of business may not be taken beyond the tax amount corresponding to the recipient's applicable rate when the supplier charges tax at a higher rate. Time charter and other rental services attract separate rates with specified credit exclusions; clarifications and illustrative examples accompany the rule.