...until they don’t.
It always happens. That huge deal you’ve been working on. Your biggest customer who won’t pay by card.
You think you can handle it. Just make an exception for this one large customer. Then you get the next deal, and you are billing two customers manually. Before you know it, you're starting to think you need a billing team.
Large companies make you jump through all sorts of hoops to get paid. Purchase orders need to be supplied, invoices need to be goods receipted, invoices are emailed one way, and chased another. If you ever then bill internationally, you'll need tax certificates and more. Then if everything is exactly right you might get paid... in 120 day payment terms.