Singapore Airlines infant seat

I’d just book as a child (so you get the right price with reduced APD) and tell them at check in, the gate and onboard that they’re an infant with a seat. As you’ve now booked you might need to call in and book for a single child but I’d just add a year to their DOB.

I’ve bothered to call in and book twice with two different airlines and I’m pretty sure they just book it as a child anyway and there has still been a bit of faff at the airport. I tell each person I dealt with so they’re aware and it’s been fine.

just before I had a kid I was delayed on a flight as someone had a seat booked for a child that was then sat on their lap for take off, so they thought they were missing someone.

Other option is to tell them you want it as a comfort seat – this might be cheaper if you’ve now booked them as an infant already