Claiming tax back on Fuel

[cjaoh]

I believe you can claim tax back on fuel when you use your own car for business use. Any clues as to where to start?

[buildersmate]

If you use your own car for business use and your employer does not reimburse you in full the mileage rates approved by HMRC, you can claim tax relief on the shortfall.
These mileage rates are 40p per mile for the first 10000 miles and 25p per mile after that. Business use mileage does not include commuting to your normal place of work from your home.
You make a claim the difference using form P87 downloadable from HMRC.
To make this clearer, if your employer only gives you 20p per mile reimbursement and you did 15000 miles in a tax year, you could claim tax relief for (0.40-0.20)*10000 = �2000 on the first 10000 miles and (0.25-0.20)*5000 = �250 on the final 5000 miles. If your marginal tax rate is 20% you therefore get 20% of �2250 back.
Frankly if my employer was not giving me 40p per mile to drive my own car on company business, I'd just tell him my car was not available to use for business purposes.

[cjaoh]

Cheers, looks like i'm due some cash back from the 'tax man'.