Ask HN: How do you handle clients who don't pay on

I run a supply role at a company during the day and I'm building a B2B tool on the side. The problem I keep running into — both at work and in my family's business — is that chasing overdue invoices is manual, awkward, and nobody has a good system for it. Most small businesses I've talked to do one of three things: send the QB/Xero auto-reminder and hope for the best, send a WhatsApp message themselves when the reminder doesn't work, or just let it slide because the relationship feels more impor