The Account Summary is a summary of information that can be added to the middle of the invoice. The summary includes:
The total amount due as of the date of the last preceding invoice or charge (assuming it pre-dates the current invoice) and even if there is a credit (negative) balance as of that date.
All payments or credits between that date and the date of the current invoice (not applied to the current invoice).
All payments or credits after the preceding date that have been applied to the current invoice.
To turn on the Account Summary:
Choose the Gear icon on the top right > Custom Form Styles
In the Action column for the form you are using, click Edit.
Choose the Content tab.
Select the pencil icon on the right middle of the preview.
Check the box for Show on invoice.
