Flagfall

Flagfall or flag fall is a common Australian expression for a fixed start fee, especially in the taxi and haulage, railway industries and toll roads - for example Westlink M7. From the Australian mobile phone industry, the expression has recently begun to spread to other English language countries, as business jargon for an initial fixed fee for establishing each phone call. The logic behind is believed to be a method used by Australian mobile phone companies to recover a component of the carriage charges they incur in completing a call to a subscriber being the termination rates, based on the price terms and conditions for the mobile terminating access service (MTAS). The Australian Consumer and Competition Commission is reviewing these arrangements.
The expression is also beginning to find its way into other businesses as a synonym to "start fee". The taxi expression is also being used in Hong Kong, New Zealand, and some other countries, but hasn't been used there as a general synonym for start fee.
Origin.
The origin is a taxi expression for the minimum charge for hiring a taxi, to which the rate per kilometre or mile and a rate per minute is usually then added up to a minimum taxicab road speed. 
When the passenger steps inside the taxicab, the flagfall condition is triggered and the taxicab driver can start the taximeter. Even if the passenger has not yet instructed the driver where to take them, the driver is entitled to the flagfall and the rate per minute component (even if the taxi is not moving). 
The term, "Flagfall" dates back to the old mechanical taximeters, which were equipped with a flag-like lever that could be seen from outside the cab. When the "flag" was up and visible, the cab was not occupied. When a passenger stepped in, the driver turned the lever down - the "flag fall" - and the taximeter started counting. In Australia, once the taximeter is counting, there are orange tariff indicator lights on the taxi head sign which light up to show the taxicab is hired.