Of course you can buy a supply (gasoline), charge the customer, and then deduct it on your taxes. You're getting taxed on your net income, which is gross income - expenses. The IRS lets us use a simplified calculation of mileage expense instead of calculating the cost of auto insurance, depreciation, gasoline, oil, repairs, etc.
What would be double dipping would be if you deducted $0.56 per mile and also deducted gasoline.
If a plumber installs a sink, and charges the customer the cost of the sink, of course the plumber is going to deduct what she paid for it from her Schedule C. |