You can add notes to your invoice using the tools under Account Setting > Design Customisation.
Take a look at this guide which shows you show to do this. There’s also a few other good pointers on there that will help you get started 
You can add notes to your invoice using the tools under Account Setting > Design Customisation.
Take a look at this guide which shows you show to do this. There’s also a few other good pointers on there that will help you get started