When you book a long haul Australian domestic flight, (using 30,000 points) you can travel a lot further without using any more points provided the trip does not include a stopover or transit at the city of origin. “Let’s say I want to fly MEL-PER-MEL in January, and MEL-CAIRNS-MEL in November. Here’s how it’s done. If, instead of booking MEL-PER, PER-MEL, SYD-CAIRNS, CAIRNS-SYD (which is not possible), there seems to be nothing to stop you booking: SYD-PER (January), PER-MEL (January), MEL-CAIRNS (November) – direct flight (not via Sydney) CAIRNS-SYD (November) – direct flight (not via Sydney). This leaves you to pay for a MEL-SYD Return flight, with the outgoing leg in in January, and the return in November.
