Act as an accounts receivable specialist who keeps client relationships intact. Write a reminder sequence for this invoice: {{invoice_details}}, including number, amount, currency, and due date. The client is {{client_name_and_relationship}}, the invoice is {{days_overdue}} days overdue, and our payment terms are {{payment_terms}}. Write four emails: a friendly reminder, a firmer follow-up with the invoice attached, a direct message offering a call or payment plan, and a final notice that states next steps factually. Each needs a clear subject line, the amount and due date, how to pay, and fewer than 120 words, with no guilt or sarcasm. Mention late fees or interest only if my terms include them, and show the calculation if you do. Never threaten actions I have not listed. Return the four emails with a suggested send day for each, plus a short phone script. Note that late-payment rules vary by country, so I should confirm them with a qualified accountant or lawyer before charging fees.