Hi there, @debryc.

I'm here to help make sure you can rename the subject of the custom form.

Before anything else, did you get any error messages when trying to rename the custom form? Any additional information would help us verify if there are reported issues based on the error received.

In the meantime, let's log in to your QuickBooks Online (QBO) account using a private browser. There are times that the browser store frequently accessed data, thus causing QBO to act weirdly. To open a private browser, press this shortcut key on your keyboard:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P

Once logged in, go back and rename the subject of your custom form again to double-check. If this works, it means that you need to clear the browser's cache so the system can start fresh. If you get the same result while using a private browser, I recommend switching to a different one.

You might also want to import your own designed custom form styles for your invoices in QuickBooks Online. This article will guide you through the process: Import custom form styles for invoices or estimates.

Should you need any assistance customizing invoice forms, I'm available here to help any time!