An overdue invoice needs a clear balance and an understanding of why payment has not arrived. Start by checking the account records.
Include the agreed purchase-order details where applicable, a description of supply, the price, due date and payment details.
Record reminders and replies. If the customer reports an error or dispute, identify which part of the balance is affected.
Prepare the evidence before referring the account. Formal steps are not automatic; discuss the options, costs and risks first.
