Thank you for following this thread, FournierFinishing. 

I'm here to make sure to be able to add customer phone numbers in the address field into QuickBooks Online (QBO).

You can add two custom fields for the email address and phone number in QuickBooks Online. Then, manually enter the details when creating the invoice. 

Here's how:

1. Click the Gear icon.
2. Under Your Company, select Account and Settings.
3. Go to the Sales tab on the left.
4. Click the Sales form content section to open it.
5. Below the Custom fields section, check two boxes and name them Email and Phone.
6. Click Save, and then Done.

I've added screenshots too.

Feel free to use these links that will help you customize your forms and add them to your reports: 

• Customize invoices, estimates, and sales receipts in QuickBooks Online
• Customize reports in QuickBooks Online

You can always add a reply below if you have an additional concern about adding customer phone numbers in the address field in QBO.  I'd be glad to assist you further. Have a good one.