You can add a note to an individual invoice after it's been generated and/or sent. This note will be visible to parents as well.
#1: Click on 'Billing' from the left-hand menu.
#2: Select 'Invoices' from the top of the Billing page.
#3: Click on the drop-down arrow next to an invoice.
#4: Click on 'Edit Invoice'.
#5: Enter your note in the 'Note' field.
#6: Click on 'Update' to save!
Things to note
Tip: adding a note to a Tuition Plan will ensure that all parents with kids on the plan receive the same note on every invoice.