I recently renewed my passport. Apparently my passport was too old so i had to apply for a new one, where the Passport number isn't the same as your IC number. I went to ICA, filled up an application for the passport and went back cause they needed to process the application, a few days later, they sent me a letter telling me the passport is ready for collection, so i made an appointment and went down. Making an appointment will save you a lot of time no matter what time u set ur appointment at, apparently if they detect that u made an appointment, they automatically put you in the fast queue when you're collecting your passport.