Everything below is fictional. A real build reads invoices from wherever the business already tracks them (QuickBooks, Xero, a spreadsheet) and sends reminders from the business's own email address and letterhead, not a third-party collections brand.
How this gets built for real
Reads invoices from wherever they already live. The fictional list here is a placeholder. A real build pulls due dates and amounts from the accounting tool or spreadsheet the business already uses, it doesn't replace that system.
Stops the moment an invoice is marked paid. No lag, no extra reminder going out after the fact, the "Mark as paid" button above shows that behavior directly.
Never moves to collections or legal action on its own. The last stage is a flag for a person to make a call, not an automatic escalation. That decision, and anything that follows it, stays with the business owner.
Email only in this template. Text reminders raise separate consent requirements (TCPA), so a real build only adds SMS for customers already opted into that channel, never switched on by default.
Not yet built for a real business. If yours has the same problem, quiet follow up costing you real cash sitting in unpaid invoices, this is the shape it would take, adapted to your accounts and your voice.