Quickbooks online v quickbooks self employed-what is the difference/which would work best for a sole trader?

For your reference

https:// quickbooks.intuit.com/learn-support/en-us/product-preferences/choose-the-right-version-of-quickbooks/00/369506

You can only convert data from QBSE to QBO.

https:// quickbooks.grsm.io/US

https:// quickbooks.grsm.io/us-promo

Hello, Avon1. 

Let me share information on the difference between QuickBooks Online and QuickBooks Self-Employed. 

QuickBooks Online plans cater to small businesses, from sole proprietorships to large corporations, and offers more advanced features than QBSE. You can use QuickBooks Online to manage bill payments, send invoices, manage 1099 contractors, and much more depending on the plan you choose. 

While the QuickBooks Self-Employed is focused on basic bookkeeping for freelancers and others who file their taxes as sole proprietors. Since it was built for people who attach Schedule C forms to their income tax forms, its quarterly tax estimation, mileage tracking, and built-in tax optimization are incredibly thorough.  

QuickBooks Self-Employed also gives you basic financial tracking tools, such as simple income tracking and end-of-year profit and loss assessments.  

Regarding the option to transfer your data from QuickBooks Online (QBO) to QuickBooks Self-Employed (QBSE) is unavailable. We can only move your QBSE data to QBO. You'll want to export bank transactions using a .CSV file and import them into QBSE. You can check this article on how to export list data in QBO. Then, import your .CSV file into QBSE. 

If you have any other concerns, or questions, don't hesitate and come back to the Community. I'm always here to help you. Have a great day.