Company Car Fuel Relief

I understand that as I will in the future be driving a company car I will no longer be able to claim the tax relief on business mileage however I am entitled to claim "tax relief on the money you’ve spent on fuel and electricity, for business trips in your company car. Keep records to show the actual cost of the fuel.". Bit of a silly question but how do I do this? When I fill my car with fuel, which is then used for both work and private mileage, should I take a mileage reading each time I fill up and apportion the mileage used for work and personal purposes, work out the average MPG for that particular tank of fuel and then allocate a number to the work mileage? It certainly is not as clear cut as claiming tax relief on business mileage. Please also don't offer me a hyper link to a section of the site, I have been searching this for a month now and there is no clear information offered by HMRC on this quandary. Some simple practical tips would be greatly appreciated. thanks Rob

Hi,

You cannot claim mileage relief for a company car. You can only claim the actual cost of fuel for business journeys but only if any amount reimbursed by your employer is less than your actual business fuel cost. 

Thank you.