I work for a company that often sends me out to job sites to do contractual work for clients. The only time my company compensates me for mileage is if I go out of town. During the past year and a half, I have been contracted out to 1 company each and every day that requires me to travel double the distance I would have normally travelled if i was at my office. I am using my own car, and my employer is not compensating me for the extra travel I’ve done over the last year and a half. Can I claim this on my taxes?



Yes you can as long as your employer confirms that they require you to use your car for business purposes.
Your employer needs to complete a T2200 for you. On it, they must show that you were required to use your vehicle for business, and how much reimbursement they provided in the year.
On your side, you must keep track of your total distance driven, the total distance for business, and your total car expenses (gas, oil, car washes, repairs, depreciation, etc.). You must keep a (daily) log of your trips, or CRA can deny the expense. You would claim this expense on form T777 in your personal tax return.
Let’s say your total auto expenses were $5000 for the year, and 30% of the kms driven were for business. You now have a $1500 business related expense. Your employer reimbursed only $500 of this (as they paid only for out of town trips). You can claim $1000 of employment expenses on your 2010 tax return.
Unfortunately no. Because you are on the company payroll.
You should have nipped this in the bud.
Most companies have a mileage allowance. Talk to accounts or HR
there must be a form for expenses. Or ask if you can use a company vehicle
for those occasions.