Billing is the subject nobody at the firm wants to deal with: reminding a client to pay is uncomfortable, so it gets pushed to next month. The problem is almost never the tone of the reminder — it's its absence.
An invoice that is never chased ages badly: the more time passes, the harder the reminder becomes and the lower the recovery rate. And manual tracking fails silently — an unmatched bank transfer, an invoice forgotten in a spreadsheet, and the firm is financing its client without knowing it.
This schedule only has value if it applies to every invoice, with no exceptions and no case-by-case judgement. That is precisely what humans do badly and machines do well.
The right division of labour: the tool matches payments to invoices, spots what is overdue and prepares the payment reminders at the right time; the firm approves each send. The system's firmness, the lawyer's judgement. That is how unpaid-invoice tracking works in Mailatio.