I am full-time employed and pay tax via PAYE but also i am self employed on the side. how do i tell quickbooks this information so it can work out my tax correctly?

Good to see you here, Patsyella.

QuickBooks Self-Employed is designed to track your self-employment income and expense as the basis for calculating your self-assessment. This version of QuickBooks is unable to calculate PAYE earnings. Although you can enter it on the Tax Profile page, I recommend reaching out to a tax accountant for some guidance.

You can follow these steps on how to add it:

1. From the Gear icon, select Tax profile under Taxes.
2. Go to the Estimated employment income field and enter the amount.
3. Click Save.

You can check this article about QuickBooks Self-Employed UK Tax Profile Set Up for more information.

You can visit our QuickBooks Self-Employed Help page anytime for more guides and articles.

Please let me know if there's anything about QuickBooks that you need help with. I'm here to help you anytime. Take care!

I'm in a similar situation. How can this detail be completed on Quickbooks Online, so that the estimate already is aware of the situation regarding tax allowance used and national insurance payments paid through PAYE role?

Not necessarily. This detail is for Online rather than Self Employed. I can't see anywhere I can detail my personal tax information to make the estimation more for me.

The Online feature is a new feature, yes it does not have that section it is working under the assumption that you are only Self Employed and that there are no dis allowable expenses as well so it would be a case of using an HMRC calculator  if you are both, we will be expanding that section. We have included an article about the income tax feature as it stands in QuickBooks Onlne