Hi there, @Micheal.

Thanks for getting back to us. Allow me to help provide some information about customizing invoice template in QuickBooks Online (QBO).

Any QuickBooks Online subscription can be able to customize invoice template. Right now, we have an ongoing issue where some users unable to select different Custom Form Styles when making invoices. Our engineers are already investigating the root cause of this unexpected hitch and working to implement a solution. 

While we're continuing to work on resolving this issue, I encourage you to reach out to our Customer Care Team to add your account to the list of affected users. This way, you'll be notified of any updates on the progress on the investigation via email. 

Here's how you can contact our phone support: 

1. Click this link: https://help.quickbooks.intuit.com/en_US/contact.
2. Select the version of QuickBooks, click Contact Us.
3. Type-in Customer Support on the search bar. 
4. And click Get the Phone number below. 

For additional reference, you can check this article on how to customize invoices, estimates, and sales receipts.

We appreciate your patience as we work through this. If there's anything else I can do for you, please let me know. I'll be around to help you out.