The payment due in sixty (60) days invoice allows an individual or company to request payment from a client/customer for services and/or goods provided. This invoice is only used if the collector wishes to give the debtor exactly sixty days to pay the balance owing in full. The balance will be written at the bottom of the invoice along with the date by which payment must be made. The invoice should also summarize the items sold or services rendered along with each associated cost. If the debtor does not make the payment before or on the due date, the collector may choose to send a Past Due Invoice to illustrate the overdue nature of the payment; additional fees or penalties may apply to a past-due payment.