The invoice message list indicates the message and the start/end dates.

These dates establish the time range for which the message will be available in the list. The right-click menu lets you add a new message, and edit or delete existing messages.
Adding/Editing an Account Invoice Message
To add or edit an invoice message:
To add a new message, right-click in the table and select New.
To edit an existing message, right-click on the message and select Edit.
This displays the Add/Edit Invoice Message window.

Enter start and end dates.
Enter the message text.
Click Save.
Deleting an Account Invoice Message
To delete an invoice message:
Right-click on the message and select Delete. This displays a confirmation window.
Click Yes to delete the entry.