Yes - you can claim - but only for duty mileage (not normal commuting mileage). The difference was about 20 ppm. I've not needed to claim it for several years (being abroad, ya'know). Basically you claim for all the duty mileage that you have done in your own vehicle, calculate what the value is at the HMRC rate is and then deduct what you have received from the RAF. There are boxes on the self assessment form for this. If I could be bothered, I could dig out my old forms. But I can't be bothered, just at the moment!
Remember it doesn't include medical or sports trips, for example - only to get to your temporary place of work - eg live and usually work at, say, Brize Norton and take your own car to High Wycombe to attend a meeting. Separately, of course, there are insurance and liability issues, but let's not open that can of worms again.
Last edited by Whenurhappy; 1st Apr 2011 at 06:20.