Overview
Open a customer under Customers and choose the Billable events tab. It lists what the customer has been charged for in the open period, with comps shown at no charge and the total at the bottom. A closed customer cannot be charged. Seeing the tab needs the permission to view billable events.
What you can do
Add a fee
Pick one of your billable products, a quantity and, if you like, a price and a description. Switch on comp to record it at no charge. Needs the permission to create billable events.
Generate invoice now
Closes the open period and creates the order for it, after you confirm. The order number is shown. If an order already exists for the period, you are told so and nothing is created twice. Needs the permission to edit customer billing.
Download the invoicing basis
Saves the period's events as a CSV file for your own checks. Needs the permission to edit customer billing.