Welcome to the Community space, @morneen.
Let me share info about categorising your paid taxes in QuickBooks Self-Employed (QBSE).
Allowable expenses are costs that are essential and directly related to running your business. These expenses can be deducted from your taxable income, reducing your overall Income Tax liability. Feel free to read this article for more info: Allowable and disallowable expenses explained.
Moreover, I recommend reaching out to your accountant in categorising your transactions for additional guidance.
You might want to learn about report that summarises all transactions that you have entered under each specific SA103F Categories. You can read this article: Transactions page versus Self-Assessment Summary page.
Click the reply button below if you have additional questions about categorizing your transactions. I'll be willing to help. Have a good one.