The Internal Revenue Service allows 56.5 cents per mile as a deduction for work-related driving as of 2013. This rate also applies to what your employer can reimburse you as a tax-free business expense. If you use this standard rate, all you have to do to document business driving is keep a mileage log. You can choose to track actual business expenses instead, but then you have to keep gas receipts, maintenance invoices, repair bills and records of insurance and car loan or lease payments – and you’ll still have to keep a mileage log.
Purchase a mileage log so you can record work-related driving in an organized way. Keep it in your car so it’s handy when you need it. You can get mileage logs at most office supply stores.
Record the starting and ending odometer readings for each business trip. The odometer is the display on your car’s dashboard that tells you how many miles the car has been driven. Subtract the starting reading from the ending reading to find the mileage for the trip and write it down in your log.
Document only your allowable mileage. Commuting to your regular work location is not considered business driving. You can count things like trips to pick up supplies, make company bank deposits and attend meetings with clients. You can also count out-of-town business trips. You may not do personal business while on a business trip for the mileage to be tax deductible although you can stop for lunch and rest breaks. Write down the date, destination and purpose of the trip in your mileage log.
Follow your employer’s rules to turn in copies of your mileage log if you get reimbursed for using your car to do your job. Employers can pay up to the IRS rate per mile. This reimbursement is tax free, but your employer has to have a record of your driving to pay you. If your company pays less than the IRS standard rate, you can deduct the difference on your taxes. For example, if you get 35 cents per mile when the IRS rate is 56.5 cents, you get to write off the remaining 21.5 cents.
Based in Atlanta, Georgia, W D Adkins has been writing professionally since 2008. He writes about business, personal finance and careers. Adkins holds master's degrees in history and sociology from Georgia State University. He became a member of the Society of Professional Journalists in 2009.