Dear Sirs,
We are writing to notify you that the invoice dated [Invoice Date] for the amount of [Total Amount] is now past the due date. The invoice number is [Invoice Number].
We have made several attempts to contact you regarding this matter, but we have not yet received your payment or a response to our previous correspondence. We would like to resolve this issue amicably and avoid any further escalation.
Please note that failure to make the payment in a timely manner may result in additional fees and/or legal action. We urge you to settle this matter as soon as possible.
If you have any questions or need assistance, please contact us immediately. We appreciate your prompt attention to this matter.
Thank you for your understanding.
Best regards