It's a pleasure to see you in Community. Welcome! QuickBooks Online enables you to add or edit the required fields, so your invoices are sent and received with confidence. I'd be glad to assist!
Here's how to enter an additional email address for your QuickBooks Online subscription invoices;
1. Open your Settings ⚙ and select Account and Settings
2. Click on the Edit 📝 in the Contact Info section
3. Ener a comma and a space next to your Company Email and Customer Email address, then enter the secondary email
4. Hit Save and then Done.
If you have any other questions, please feel free to reach back out. We're always happy to help!
Thanks for getting back to us here. I suggest contacting us outside of Community, so we can work with you personally, and look further into this from our end.
Schedule a Callback or start a Chat: click (?) Help in the upper right in QuickBooks Online > enter "Contact support" > hit Contact Us > provide a brief summary of your situation > hit Let's Talk > choose Get a callback or Start a Chat.