GST is added on top of all fees charged to drivers and passengers; HST does not apply.
Driver payout fee
GST is charged on the driver payout fee, not the entire payout amount. For example, if a passenger books a trip for $50, the amount of GST paid by the driver is calculated as follows:
Payout: $50
Payout fee: $1.57 (including 5% GST)
GST portion: $0.07
Passenger booking fee
GST is charged on the passenger booking fee, not the entire booking amount. For example, if a passenger books a trip for $20, the amount of GST is calculated as follows:
Seat price: $20
Booking fee: $4.20 (including 5% GST)
GST portion: $0.20
For more information on taxes and how they affect drivers, read this article.