Originally Posted by
Merlinrnr
It can't be done online. You have to call in to book it. Ask for the online discount anyway. They will give it to you because it can't be booked online. And you can also do a stopover in HKG or SIN if you're interested.
This is good advice, but just to expand on it a bit:
1. As Merlinrnr implied, you are entitled to a 15 percent mileage discount (in comparison to the SQ mileage redemption chart) if booking online, but also can get it even if calling by phone in a situation like this where booking a combo F/J online is not possible.
2. Based on my experience booking mixed class F/J awards (including recently), another complication is that some SQ CSRs don't understand the rules regarding this. The best ones tend to be at the KrisFlyer Membership Services number in Singapore: +65 6789 8188. I'd suggest calling/skyping this rather than regular reservations numbers for SQ. Even then, there's a chance you'll reach a CSR who'll incorrectly tell you that you must book two separate award tickets, or that you can't get the discount, or whatever. If that happens, politely end the call and call back to reach another representative.