Self assessment - Employment Section - UK tax taken off pay

Hello, I am completing my self assessment form. For the question "UK tax taken off pay in box 1" does this require me to calculate both income tax and national insurance contributions, or only income tax? For example, if the gross pay was £200, and the NI was £10 and the income tax £20, would I answer the question "UK tax taken off pay in box 1" as £20 (only income tax) or £30 (NI and income tax)? My second question is how to show tax refunds on the self assessment form. For example, if I paid £300 in tax to an employer, but was refunded £100 by the same employer, would my answer to "UK tax taken off pay in box 1" be £200? What happens when refunds are spread across different employments? For example, Employer A taxed me £152, but Employer B realised that I was under the taxable threshold, and refunded me £152 (showing as a minus on my payslip). How would I translate this information onto the form? Would Employer A, 152.00 and Employer B, -152.00 be correct? Can you put negative numbers in the answer box? Many thanks for your help.

Hi Hazel1939,
It is only the tax deducted that you would enter.
If an overall refund and the tax deducted figure on your P60 has an 'R' next to it, enter the amount as a negative value.
Thank you.