Self Assessment tax checker

Radshire

Hi,

I have been asked to help prepare a self assessment tax submission and have got all of the information in one place. I’ve built a workbook to perform the calculations but before I give this over to be entered into the self assessment tool, I want to make sure my calculations are right.

Does anyone know of a good online self assessment tax calculator?
I know that you can check before submitting on your own self assessment, but this is no good if you are filling in for someone else.
Most of the ‘tax calculators’ I have found are those which can be used for estimating net income, but do not have the complexity which comes with having multiple income streams.

Any help greatly appreciated.

Thanks