How do I put TAX INVOICE at the top of an invoice so it will print TAX INVOICE

Hello, @jnkendal.

You can change the name of the form from the Custom Form Style window. I can guide you on how to do it.

1. Go to the Gear Icon.
2. Choose Custom Form Styles.
3. Click the New Style drop-down arrow.
4. Pick Invoice.
5. Choose the Content tab.
6. Click the Pencil Icon on the first part of the invoice.
7. From the Form section, change the name Invoice into your desired name.
8. Click Done. 

You can read through this article to learn more about customising your sales forms: Customise your invoices, quotes and sales receipts in QuickBooks.

Also, for more insights about managing your sales forms, you can check these articles:

• Add, customise, or remove logos on sales forms
• Email and customise sales form

Let me know if you have other questions and concerns. I’m always here to help.