new customer details

I can share some information with adding customers in QuickBooks Online, @Dixeee86

At this time, you can set one email for each of your customers in QuickBooks Online (QBO). Adding additional email addresses would be a great addition to the current features that we have, so I’ll take note of it. In the meantime, you can add the email address in the Notes section. 

I also encourage you to leave feedback from within the product. Here are the steps:

1. Go to the Gear icon and select Feedback.
2. Provide your product suggestion.
3. Click on Next to submit feedback.

You can check out this article for more information about providing feedback to make the program better: How do I submit feedback?.

For more information about adding or editing a customer profile to add the other email address on the Notes section, check out this article: Add and manage customers in QuickBooks Online. 

Here's detailed guidance on how to send summaries of your customers' invoices, payments, credits, and balances: Create and send customer statements in QuickBooks Online. 

Let me know if you have further questions about adding customers to QBO. I'm always here to answer them for you. Have a great rest of the day!