This area is poorly documented and there is no direct refernece to this situation on the HMRC site.
My understanding is as follows:
If you have a private vehicle used for business mileage AND you have all personal and business fuel paid for by your employer, the following points apply (If I am definintely wrong, please someone tell me).
- You can forget the 14800? valuation for a fuel card with a company car - this does not apply to the use of a private vehicle - so you can forget all that emissions stuff etc.
- You can get relieve on the Mileage Allowance Rate - thie is 40p a mile up to 10,000 p.a. and 25p a mile above 10,000 miles p.a. I understand you needto keep a record of your biz trips and submit them to the IR. You can then claim this back - it can therefore be significant.
However, if your employer is paying you in some manner, fuel card or expensed, then you have to subtract the employers contribution from the MAR rate - i.e. if you get 10p of fuel for each business mile you do from your employer, you can only claim back from the IR 40p - 10p = 30p for each mile you do. This is for less than 10,000 miles. If you do more than that the marginal rate drops so you are only getting 25p-10p = 15p per mile that you can claim back.
The private mileage can only be logically taxed as a benefit in kind - i.e. at whatever your marginal rate of tax is 20% or 40%. I would expect your employer would declare this annually to the IR - or indeed you complete it on your tax return.
All seems quite simple ( if it is correct - which I think this mostly is). Strange that nobody in the government can explain it on a web page anywhere and they are all so confused in the IR...!
P.S. If this is wrong, please someone tell me!