Originally Posted by
Kacee
You won't be able to check bags through on a separate ticket to a non star alliance carrier. So you would have to clear immigration and pick them up at SIN on the outbound, and (probably) also at SYD on the return.
OP is spending several days in Australia on the return so they will have to pick up their bags regardless of who they fly from DPS-SYD.
OP, assuming you are traveling on a US passport then entry/exit in SIN is super easy and laid back. You will have to pick up your bag in SIN which means you will have to clear immigration, collect your bag, go through Customs and then go to the departures level to check-in for your next flight to DPS. The only way to avoid this is if you ticket IAH-DPS in one ticket or if you purchase SQ (Singapore Airlines) as the carrier from SIN-DPS. If the latter then UA can tag your bag all the way through and you can simply stop by the transfer counter in Changi airport (SIN) to collect your SQ boarding pass without going through immigration and customs.
If you will go through I&C please allow 2 hours connection time. SIN is a mega efficient airport (maybe the best in the world) but chances are you will pick a LCC between SIN and DPS and they are unforgiving with check-in deadlines.
-RM