Officially, there is no such thing as "discount taxis".

It is illegal for taxi drivers to negotiate the fare.

Taxi drivers are required by law to charge the meter fare, not more and not less. Passengers must also pay the meter fare.

You can find taxi fare information at this link:

http://www.td.gov.hk/en/transport_in...ong/index.html

Nothing to stop you from asking if the taxi driver will give a discount. Don't forget that the taxi driver may renege on the discount on arrival at destination and you will end up paying the meter fare. Such agreement is not enforceable as it is an illegal contract.

Some third class hotel concierge may have connections with some taxi drivers who will offer a discount. If you're staying at the Conrad, they will definitely not have anything to do with such practice as it is illegal and they have a reputation to keep.