Thanks for reaching out to us, @actionglass. I'd like to help share some information about making changes to your customer's account in QuickBooks Online. 

To properly set up a parent account for a customer, it is important to follow a specific sequence. First, you should make any necessary changes to the sub-customer's account. Once those changes have been made, you can then designate it as a parent account by editing the sub-customer's profile and unchecking the Is a sub-customer checkbox.

See the screenshot below for your visual reference.

Please check this article on how to add, delete, merge, and restore customers in QuickBooks Online: Manage your customer list.

In addition, the links below contain resources that will guide you on how to handle customer-related activities such as creating invoices, managing payments, customizing sales forms, and processing credit or refunds, to name a few.

• Invoices and payments
• Sales and customers

Reach out to me again if you have any clarifications or questions on how to manage customers in QBO. I’ll be around to assist further. Have a good one.