Hello Frank,
Adding customers is really easy to do in QuickBooks Online. I'd be happy to explain how you can add an additional contact for each of your customers.
Although there's only one name you can add to the "Display Name" for your customer, you're always able to add notes in the customer information so that you have access to additional contact information. To do this, follow the steps below.
1. Click the Sales tab on the left navigation menu, then select Customers.
2. Click New Customer.
3. Enter your customer's information in the appropriate fields.
4. Click the Notes tab towards the bottom of the box. Enter any additional contact information you'd like to store in the system.
5. Click Save.
Additionally, if you'd like to email statements, invoices, or sales receipts to multiple recipients, you'll simply add an additional email to the "CC" field. Do this by clicking the small blue link under the Customer Email field on your sales form.
I hope this helps you reach your goal. If you still have outstanding questions, please let me know and I'd be happy to help you further.
Cheers.
