This is a really easy Maths question - economics related?

It isn't all a matter of fiddling the tax return or paying a crooked accountant to do it for you. Everyone is entitled to a personal allowance before tax is assessed. In addition, memberships of professional bodies are allowed against tax; and these are very likely to be substantial for big earners. Institute of Bankers, Institute of Directors, Institute of Chartered Accountants; maybe some charitable societies such as Royal Society of Arts, Friend of the British Museum and British Library, Royal Academy, Thomas Coram Foundation, National Trust and so on. These can mount up to tens of thousands every year and they are not a fiddle. They are real expenditures and are allowed against tax - and they enable important worthwhile charities to continue their work.

Also, some everyday expenditures are allowed against income if they are a requisite for the job or in support of pro bono work for a charity. This could include new formal business clothes [for men and women], computer hardware and software, travel, some hospitality and such like.

Does that give you some ideas?