How do you chase a late invoice without losing the client?
A late invoice is awkward for both sides. The client knows it is late, and you know they know. The trick is to make paying easier than ignoring you.
1. Send the reminder before it is late
Three days before the due date, send a short note with the invoice attached and a link to pay. Most late payments are forgotten ones.
2. Keep the first chase friendly
On the day it is due, assume good faith. Ask whether they need anything from you to process it.