The Past Due Invoice Letter is an essential business document used when a payment becomes overdue according to previously agreed terms. Typically issued after the payment deadline has passed, this document serves as a formal reminder and demand for payment under New Zealand law. It includes critical information such as the original invoice details, outstanding amount, payment history, and clear payment instructions. The letter should comply with New Zealand's Contract and Commercial Law Act 2017 and Fair Trading Act 1986, maintaining a professional tone while firmly stating the payment requirement. This document is particularly important as it creates a paper trail for debt collection purposes and can be used as evidence in legal proceedings if payment issues escalate. It's designed to balance the need for payment collection with maintaining professional business relationships in the New Zealand commercial context.

1. Sender's Details: Full business name, address, and contact information of the creditor

2. Date: Current date of the letter

3. Recipient's Details: Full name, business name (if applicable), and address of the debtor

4. Subject Line: Clear indication that this is a past due invoice notice with reference number

5. Invoice Reference: Original invoice number, date, and amount

6. Outstanding Amount: Clear statement of the total amount due, including any late fees or interest

7. Payment Timeline: Original due date, current overdue period, and requested immediate payment

8. Payment Instructions: Bank account details or other payment methods accepted

9. Consequence Statement: Professional explanation of next steps if payment is not received

10. Closing: Professional sign-off with contact information for payment queries