Hello melaniejswan, 

It is not possible to upgrade from QuickBooks Self-Employed to QuickBooks Online due to feature differences. 

If you use QuickBooks to produce a Tax Summary for Self-Assessment we would recommend continuing with the Self-Employed product. You can however take a trial of our online product from the link below to make sure this is the correct product for you before switching.

https://quickbooks.intuit.com/uk/

Thank you