When creating an Invoice for a client, the first step is to create a Bill Batch. Bill Batches are created to organize different billing periods for your business. Many companies bill on a set schedule, bi-weekly, the first of the month, or on some other frequency. Other companies bill on a variable schedule, such as when a project ends, or a major client hits a certain number of dollars in billables, or even when the billing administrator finds the time. No matter how you bill, when you make the decision to bill your clients, it's helpful to organize all the hours that you bill in one place. A given entry will only ever be part of one Bill Batch, which also helps prevent hours getting billed more than once. Also, until an entry is added to a bill batch, it will remain in the unbilled area. Once a Bill Batch is created you store a comment about the Bill Batch which will show up in Bill Batch History. From Bill Batch History you can also create a new comment, or edit an existing comment.

Bill Batch History Tab in Accounting Center:

Comments do not affect the billing process in any way, yet can serve an appointment organizational function. Comments can be used to give you a general idea about the group of hours you are billing. for example, you might bill high-risk clients together, so another administrator can work that list with follow up calls as soon as the aging hits thirty days. you would perhaps leave a comment for this label that says "high risk clients." you might also bill by large and small clients in separate bill batches, or bill by various divisions, or the clients under particular partners. the reasons are as endless as businesses are unique.