Subject: Invoice Due: Final Reminder | [COMPANY_NAME]
This is a reminder that invoice #[INVOICE_NUMBER] was due on [DUE_DATE] and remains unpaid. I have attached a copy of the invoice to this email.
Our numerous attempts to contact you have gone unanswered and hence we are contemplating legal action towards you and your company.
To avoid legal consequences, please make the payment immediately. If we don’t hear back from you in 24 hours, we will have no choice but go the legal way.