I'm here to share how QuickBooks Self-Employed handles your self-assessment.
Just to clarify, what specific personalisation are you referring to? If you're referring to changing the SAF103 categories of your transactions, you can easily do so by locating the transaction and clicking on its assigned categories. Also, the ability to create custom categories are currently not available. Lastly, should you want to make changes on your Tax Profile, here's how:
Go to the Gear.
Select the Tax Profile.
Toggle the Tax Year.
Make the necessary updates.
On the other hand, you'd just want to make sure that all of your self-employed related income and expense transactions are recorded in QuickBooks. This way, the system will automatically calculate and generate your Self-Assessment summary. You have 3 ways to do so: