In business IT, billing software refers to programs that handle the tracking of billable products and services delivered to a customer or set of customers. … These types of programs automate much of what used to be a time-consuming process of preparing invoices or other documentation.
An invoice, bill or tab is a commercial document issued by a seller to a buyer, relating to a sale transaction and indicating the products, quantities, and agreed prices for products or services the seller had provided the buyer.