Hi tomnewkirk08. For it to appear on every invoice, you would need to create a custom template for the invoice. I'm going to list the steps below for you as well as include a quick video on the process so you have a nice visual representation as well. Here they are:
Creating the Template
Set the template as default
This invoice template will now be the default for all invoices. If you have more questions about the customizing we have a great article as well about customizing form template. Feel free to also ask me any other questions you may have.