[widdershins]

> With respect to the income tax, it is possible for higher earning (not by US standards) employees to receive a bonus and actually take home less money than before they received the bonus.

What are you referring to here? Higher rates of income tax are only taken on the money earned over the band. So If you earn £50,271, you pay 20% on £50,270 and 40% on £1.

Are you referring to some other kind of tax then?

https://www.gov.uk/income-tax-rates

[Sholmesy]

As well as the childcare benefit removal others have mentioned, you also begin losing your "tax free allowance".

The marginal tax rate for 100k -> 125k is 60% (due to losing the ~£12k tax free allowance)

  "Your personal allowance goes down by £1 for every £2 that your adjusted net income is above £100,000. This means your allowance is zero if your income is £125,140 or above."

[zipy124]

there are benefits such as child tax credits which are not tapered. You either get the full benefit if earning £99,999 a year, or nothing at £100,000. This benefit if you have children can be worth tens of thousands of pounds, thus resulting in a net loss. If you look at income data after tax this causes a weird drop in take home pay in the roughly 100-130k range, where people just salary sacrifice all their extra pay to make sure they are under 100k. This is not productive to the economy.

[UK-Al05]

After 100k, you get childcare benefit removed. This mean less money you pocket going from 99999 to 100k.