Originally Posted by
madrooster
QF do not allow combining any Y and J fare together. However, you can combine any J with any F, and any Y with any W on a half return basis. Only those two combinations are permitted.
Looking at the fare rules for LHR-SYD, there is nothing listed that indicates that this is not permitted. Doing a check on ITA , outbound S and inbound T prices up quite happily
Subject to availability, I cannot see that there should be any problem making the booking over the phone with QF or with a travel agent