When Commerce Sync is transferring your sales information, there are two options for what customer is used when creating the invoice:
Daily Summary, One Default Customer
One of the most common ways merchants are transferring their sales through Commerce Sync is with a daily summary of the sales, using one default customer. Commerce Sync will create a generic customer in QuickBooks based on the name of your point of sale or payment solution (Clover Customer, Square Customer, Authorize Customer, Stripe Customer, etc.)
Here is the setting in the Commerce Sync Dashboard:
Individual Transfer with Customer Detail
If you have customer information in your point of sale or payment solution Commerce Sync can transfer this information into QuickBooks. The details transferred do not come from the credit card information, but from the Customer/Contact database in your point of sale or payment solution.
Customer detail can transfer differently based on the point of sale, payment solution and whether you are using QuickBooks Online or QuickBooks Desktop. For more information, please reach out to firstname.lastname@example.org.
The accounts, items and customers in your Commerce Sync settings are populated by the information Commerce Sync receives from QuickBooks. Commerce Sync will create place-holder items and accounts to use when you install and connect to QuickBooks.