From: Business School 101
and Alamo Bookkeeping Associates
Well there are lots of them, however I will discuss some of the big ones. The main item I see fall through the cracks is mileage for use of your car/truck, etc. and office expenses.
There are two ways to record car expenses; the easy way and the hard way. The hard way is to keep track of all your actual expenses. These are: gas, repairs and maintenance, insurance, and a tricky item called depreciation of your vehicle. If your vehicle is considered a vehicle for hire, such as a taxicab, van, limo, bus etc, then you must track actual expenses; you do not have another option.
However if your vehicle is not a vehicle for hire then you have the choice of tracking your miles. This would be the easier way to record car expenses. This little item is often overlooked by business owners, especially new ones, who haven't got a clue how important this is. This item will usually turn out to be a large amount when tax time comes so it is very important that you keep track of it.
Next: how should I keep track of my miles?