We collected money from everyone and bought a bunch of flowers and a message board.
Don't worry about collecting money anymore. What will be, will be.
I’ve got tons of work I have to catch up on. Anyway, maybe I should start collecting money from my clients.
When you collect gold you are collecting money (or doing money collection). Of course, back in the day gold was like money, which is why this word works the way it does. Hopefully you don't have to deal with too much 集金 in your daily life. We'll try to keep WaniKani nice and reasonably priced for you.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.