Originally Posted by Diamond Seats

Is your SIN-CGK-SIN-MNL same day?
If yes, what you can do is to check in for your flight SIN-CGK (separate tix), then tell the agent to do a return check-in for CGK-SIN-MNL. And you can check-in your bags for SIN-MNL. Remember that SQ allows you to check-in bags 48 hours prior.