Hi there, steve37.
For now, we can't directly transfer data from QuickBooks Online to QuickBooks Self-Employed. However, you can import the customer payments either using a CSV file or connect your bank in the program. Here's how:
Add bank account
If you can't see your bank, you can import the payments using a csv file. Here's how:
With regards to your invoices, you can recreate them manually in QBSE. Follow this article on how to recreate them: Easy Invoicing In QuickBooks Self-Employed
Let me also share this usage guide to help you navigate QuickBooks Self-Employed: QBSE Product Usage Hub.
Add a reply below if you have other questions.