You need to use the photo ID smart card to get the Total Mobility discount.
Present the card to the driver at the beginning of the trip. The taxi driver will swipe the card at the start of the trip and then again at the end of the trip. This will record all the necessary information for the discount. The driver will then let you know how much you need to pay.
A return trip in the same taxi (a trip from origin to destination and back to the point of origin) is counted as two trips.
When two or more people with disabilities share the same taxi, only one smart card should be used for the trip.