in expenses, how do I categorise a payment to my private pension?

In QuickBooks Self-Employed, you’ll need to categorize pension payments as Personal, Allison. 

This is because contributions to your private pension are considered personal expenses, not business-related expenses. In the Self Assessment tax return, these will fall under disallowable expenses, as they cannot be deducted as part of your business costs. 

I still recommend reaching out to your accountant for assistance to ensure everything is categorized correctly. Also, you can refer to the official HRMS guidance.
 

Keep us posted if you have any follow-up questions.