This discussion clarifies the rules around claiming GST input tax credit (ITC) for rent-a-cab services. While generally ITC is not available for such services, an exception exists if the service is used for making an outward taxable supply or as part of a taxable composite or mixed supply. If your business provides mixed services sold for a single price, you may be able to claim the ITC.
the input tax credit in respect of such goods or services or both shall be available where an inward supply of such goods or services or both is used by a registered person for making an outward taxable supply of the same category of goods or services or both or as an element of a taxable composite or mixed supply