Why use Customer sub-account?

Thanks for checking in with us, howardjennings.

If you are referring to setting up a sub-customer of main customers (also known as parent accounts), we use it to track individuals who are part of a group or specific accounts for a larger organization. First, create a regular customer account for the group or organization. Then add each member or account as a sub-customer. Let me show you how: 

1. Go to the Sales menu.
2. Select the Customers tab
3. Tick New Customer.
4. Choose the Is sub-customer checkbox.
5. Enter the sub-customer’s info.
6. In the Parent▼dropdown, select the parent account. Tip: Select Bill with parent or Bill this customer if you want to bill sub-customers individually or as part of the group.
7. Press Save.

Parent accounts can have up to four levels down of sub-customers. To learn more about this one, see the Add and manage customers in QuickBooks Online article. If you are referring to creating subaccounts, we use it to break down your expenses, income, and more into greater detail. Where in you can divide your utilities account into subaccounts to track different types of utility payments, like gas, telephone, water, and so on. See Create subaccounts in your chart of accounts in QuickBooks Online article for more details. 

Feel free to visit our Sales and customers page for more insights about managing your company's income and customers.

I'd like to know how you get on after trying the steps, as I want to ensure this is resolved for you. Please reply to this post and I'll get back to you. Have a great day ahead. 

We use it for customers with multiple locations so it's easy to find certain invoices for a certain location but because it's billed with parent the Client receives 1 statement with the total for all invoices.