The IRS allows you to deduct certain mileage you drive in your personally owned vehicle (POV) from your taxable income. There are different rates for miles you drive that are related to business, moving, receiving medical care, or charitable purposes. The cents per mile rate is adjusted each year based on the cost of owning an automobile. In 2009, the rates are 55 cents per mile for business-related mileage, 24 cents per mile for miles driven for moving and medical expenses, and 14 cents per mile for miles driven for charitable purposes. In addition to mileage, you can deduct tolls or parking fees related to these purposes. However, be sure to document the mileage by keeping a complete and accurate log of the miles you've driven.
Make a column for the date of the trip. Every time you make a trip that you plan to deduct, note the date.
Make two columns, for the starting and ending odometer reading. Each time you start and end a trip, write down the odometer reading so you can verify the distance traveled to the IRS.
Make a column for the total distance traveled. You can find this by subtracting the starting odometer reading from the ending odometer reading.
Make a column for noting where you drove and why you made the trip. This section is vital to defending your claims, because you must be able to show that the trip you took was for a legitimate deductible purpose rather than a personal trip.
Make a column for any extra tolls or fees you paid during the trip. This amount can be included in addition to the per-mile rate for qualifying trips.
If you find keeping a mileage log too cumbersome, you might want to consider purchasing one of a number of digital products designed keep the log for you.