Hello Nezzer,
I can understand the benefit of being able to send invoices to multiple members of your team. QuickBooks Online provides the ability to apply additional email addresses to your customer profile, so you don't have to enter them manually when creating your forms. I'd be glad to assist!
To include email contacts on customer profiles, you'll open Sales, then Customers. Select a customer to Edit. In the Email field, enter the desired email addresses, separated with a comma and space. Be sure to Save the updated information. In addition, you can enter email addresses directly on the invoice you create, as you see necessary.
If you have any other questions, please feel free to touch base with us again. We are here to help!