How to calculate taxable income - to enter in personal tax account on HRMC website for tax code

[NoMoreLimbo]

Hi all. My tax code has been changed to something very strange. HMRC now want me to update my estimated taxable income for the year ahead. I have no other income than the one from my job (I am in England). There is a potential bonus but not guaranteed. I also have a sum deducted from my salary every month that goes into pension saving. Do I add up my salary, plus the bonus (even if it is not guaranteed) and do I deduct the pension (salary sacrifice)? What of NI contributions? Leave in or remove?

I would ignore the bonus and use the gross income but after the salary sacrifice pension. The bonus will only matter if it pushes you into a different tax code where your personal allowance will get reduced.