Trash Flow uses the term “invoice” as defined in modern accounting: a unique, dated, itemized bill for your goods or services providing individual prices, the total charge, and terms of payment. Below is an example of a bill for an invoice-billed customer.

Western Disposal, Inc.
Invoice 861
Jul 2, 2010
The Dew Drop Inn, Acct.# 1468
Jul 1–Jul 31: CSC Container Service, 530 LaSalle St., 4-yrd front load, $68
Jul 1–Jul 31: CSC Container Service, 530 LaSalle St., 8-yrd front-load, $110
----------------------------
Total Amount Due: $178.00
NET 30

In the above example, Western Disposal is billing the Dew Drop Inn $178 for regular disposal service on two containers. The invoice is generated on Jul 2 and will be mailed to the customer, who then has 30 days to pay the invoice. The Dew Drop Inn will presumably be billed the same amount for the service again in August. If the customer did not pay their bill in July, their August bill will not reflect this—it will be a brand new invoice for $178. When a customer is set to pay by invoice on their Rates tab, they will not see a bill for the entire amount they owe across all invoices you unless you send them a billing statement. Note that for invoice-billed customers, each payment must be applied against a specific invoice. Check System > Properties > Billing Options > Auto Payment Application to set all payments on invoice-billed customers to be applied to the oldest open invoice.

Billing and payment by invoice is common practice in the business world, but rarely used when billing for residential services. Like most residential utility bills, trash service is generally billed by statement. A statement is a bill showing the total amount owed for any and all goods and services at the time the statement is created. In the above example, if the Dew Drop Inn did not pay their July bill, a statement created in August would be for $316: $178 for service in August and $178 for the unpaid bill from July.

If you are using Trash Flow’s advanced billing module, customers can be set to pay by invoice or by balance on the Rates tab of their customer information window. However, even if a customer is set to pay by balance, you can still send them invoices if they wish. In these cases, the customer’s payments will simply be applied against their entire balance rather than against any specific invoice.