Hey loonie50,
QuickBooks Online gives you the tools to create attractive, professional-looking invoices, estimates, and sales receipts. You don’t need to be a designer to make eye-catching custom forms. They're a great way to enhance your business' brand.
Here's a helpful article that will guide you through the process of customizing not only invoices, but also estimates and sales receipts: Customize your invoices, estimates, and sales receipts in QuickBooks Online.
As explained in the article, you'll create a new template, select your designs, customize the information, personalize your email, and learn how to apply this template to your sales forms.
Another option you can explore is creating a custom form style from a DOCX file. Here's more information about that: Import custom form styles for invoices or estimates.
I hope this helps. If you have any other questions, please don't hesitate to reach out to our tech support team.
Cheers.