In some instances, you would like to leave a note on a particular invoice that won't be able to be seen by the customer. Some times, this invoice may be flagged or other non-financial reasons as to why the invoice may need some more attention. Adding an invoice note is a great way to leave a message to another admin without your customers being able to see this information. To do so, you would just need to go to the invoice page and select the "Actions" drop down. From there, just select "View/Add Invoice Notes":
From there, you'll be brought to a new page where you can add a note to this particular invoice:
In this scenario, I'll be leaving a note for the next admin to see that we've have trouble processing this student's credit card:
Afterwards, we just select "Save" and the note now displays on the bottom of this page:
Once done, leaving any notes, just select "Back to Invoice Details". You'll note that once you go back to the invoice page, there's a new flag indicating that there's a note on the invoice:
It's always good practice for an admin to check the invoice notes to check for other information specific to this customer's invoice.