Taxation of Cash Forgone for Electric Vehicle. Car Allowance, BIK, EV, Income Tax.

I receive £6120 pa (£510pcm) as a car allowance. I can elect to take as cash or to use to finance a leased company car through my employer. In March 2022 I commenced a lease for an electric vehicle (0 CO2 emissions) with a P11D value of £41601. There was a trade up value of £272.38 pcm as the cost exceeds my car allowance. My CO2 based BIK < £6120 thus I believe I should be paying income tax (@40% as a higher rate tax payer) on the cash forgone iaw HMRC rules. [The higher value is selected as the relevant taxable value] As such the total monthly cost of the vehicle I would expect to be £272.38 (Trade Up) + £204 (40% of the £510) = £476.38. However, the lease company automatically take 100% of the cash forgone (not 40%) which results in the monthly cost being £782.38. Please advise if the taxation being applied is correct?

Hi David Elsey,
We would need to access your record to check what has been submitted for the company car.
You can contact HMRC:
Income Tax: general enquiries
Thank you. 

Hi, not a HMRC Admin but it looks correct. You seem to be taking what the £510 would've cost you in tax in trying to work out the cost to you but you would never have the £204 even if yiu took the allowance so that can't be a cost to you. The cost to you would be the £296 you would've received as pay had you taken the allowance. But salary sacrifice you sacrifice the gross, not the net. So the correct figure is the £510. Sorry it isn't better news I'm bearing.