Company Car Tax 20%/40%

twh

Evening all,
When considering company car tax, does anyone know if there is a sliding scale for the tax.
e.g. when earning £50k, the rate would be 20%, but when earning £51k does the rate automatically become 51k or is the 40% only on the additional over the threshold?
Alternatively, does the marriage tax allowance allow mean that £1.2k personal allowance can be transferred to my wife and therefore one would only pay the 20% rate....?

molerat

Company car benefit is effectively extra income - you add the benefit to your other income and that is your total income for tax purposes. You only pay higher tax on the amount over the  threshold. You cannot receive marriage allowance if you are a higher rate payer.  Marriage allowance does not transfer an allowance, it reduces the recipients tax bill by £252.