How may I remove "powered by Quickbooks" and other Quickbooks branding from my invoice emails to customers?

Thanks for reaching out, leland-whitlaute.

Allow me to share some information concerning removing the "powered by Quickbooks" and another branding from QuickBooks Online.

The ability to get rid of the branding in QBO is unavailable. It's working as design. 

Here are articles on how to personalize your sales forms in QBO:

• Customize invoices, estimates, and sales receipts in QuickBooks Online.
• Import custom form styles for invoices or estimates.

Feel free to visit the Community at anytime if you have any other questions. We're here to help.

@leland-whitlaute 

Consider switching to QB Desktop and deploy a private cloud if required.