Thanks for checking with us, Steven Lockie.
Allow me to share some information regarding the correct process and accounting for P45 income within QuickBooks Self Employed.
It is correct that you would record it in the tax profile; however, you would adjust the personal allowance section because the PAYE would affect how much allowance you have remaining. If you have exhausted your allowance, you can change the figure in that section to zero. This means that the income tax has been calculated correctly.
If you need more details about this, we can coordinate with your tax professional. They will be able to advise on how to report this type of expense and answer any tax-related questions you may have.
Additionally, in case you need help with the categorisation, we can refer to this article: Updates to expense categories in QuickBooks Self-Employed. This will help guide you on how to report your self-employed income and expenses. Even if the article is for QuickBooks Self-Employed (QBSE) US, the same concept can be applied to your UK account.
If there's anything else I can help you with, please let me know. I'd be more than willing to lend you a hand.