Hi lorikennedy,
I can see the importance of adding a post-it note on an invoice. While this feature is unavailable, recommend sending feedback to our developer's team. Here's how:
- Click the Gear icon.
- Under PROFILE, select Feedback.
- Enter a few words to describe your suggestion.
- Click Next.
Furthermore, I've added this article as your guide about managing invoices: New estimate and invoice layout.
You can always post in the forum whenever you have product suggestions.
