I freelance, and chasing invoices is the part I dread. My reminders are either so soft they get ignored or so blunt they damage the relationship.
Build a prompt that takes {{client_name}}, {{invoice_number}}, {{amount}}, {{days_overdue}}, and a {{relationship}} note ('long-term, usually pays late' vs 'new client'), and writes a payment reminder that escalates appropriately: a gentle nudge under 14 days, firmer with a clear due date past 30, and a final-notice tone past 60 — always professional, never threatening or guilt-tripping. It should restate the key facts (invoice #, amount, original due date) so the client can act without digging through their inbox.
A strong solution adapts firmness purely from {{days_overdue}} and {{relationship}}, offers a payment-plan line only when overdue is high, and keeps every version under 120 words. Show all three escalation levels generated from one prompt and one set of inputs.