If you use your own car on business-related journeys, such as travel from your office or place of work to visit a customer, this will be treated as business travel. This also applies if you use a van, motorcycle or bicycle. Travel to and from your normal place of work is not considered to be work-related travel.
Any allowance paid to you by your employer for using your own vehicle for business travel will only be taxable if it is paid above the maximum amount for each mile approved by HM Revenue and Customs. This is called the Mileage Allowance Payment (MAP).