Who is the "tax man" and how do I pay Tax?

[rusty]

I'm driving a car and the petrol is paid for the company (private or business) and I was told that I am paying tax for the petrol but I should get refunded for the tax I paid for business... how do I do that? Im doing around 12000 miles a year so that should be quite a lot. (??)

BUT on another thread you say that you have just passed your test