the rule for claiming a percentage of house bills is:....
If you have 1 room dedicated as an office...
you cannot count kitchen and bathrooms, but you then add up all the other rooms in the house for the number you divide you bills by...
EG; a 2 bedroom house with a through lounge diner
1 bedroom is office you then have 1 bedroom and a lounge = 2 rooms
so you divide all your household bills by 2
that includes water electric gas council tax broadband telephone etc... however you can be liable for capital gains tax if you do this......
If you rent however
As for mileage the first 10,000 per year can be claimed at 45p per mile... however you cannot claim mot oil service etc as all included in the 45p per mile...
hope this helps.
this was all from the taxman by the way and not made up....