Can I send my existing customers and parts to QuickBooks in one go?

Yes. The QuickBooks set-up page has one-time bulk pushes for customers and for parts and services. Before the customer push, BytePhase shows how many customers are not yet in QuickBooks and roughly how long it will take. The push runs in the background and you get an email and in-app notice when it is done. If a customer with the same name already exists in QuickBooks, BytePhase links to that record instead of creating a duplicate.