Keep an eye out for these often-overlooked ways to cut your tax bill.

It's simple: The more tax deductions your business can legitimately take, the lower its taxable profit will be. And in addition to putting more money into your pocket at the end of the year, the tax code provisions that govern deductions can also yield a personal benefit: a nice car to drive at a small cost, or a combination business trip and vacation. It all depends on paying careful attention to IRS rules on just what is, and isn't, deductible.

When you're toting up your business's expenses at the end of the year, don't overlook these 14 common business deductions.

1. Auto Expenses

Operating a car is expensive. The good news is that if you use your car for business, or your business owns its own vehicle, you can deduct some of the costs of keeping it on the road. Mastering the rules of car expense deductions can be tricky, but well worth your while.

There are two methods of claiming expenses: You can either keep track of and deduct all of your actual business-related expenses, or you can deduct a certain amount for each mile driven (the "standard mileage amount," which is 44.5 cents per mile in 2006) plus all business-related tolls and parking fees.

As a rule, if you use a newer car primarily for business, the actual expense method provides a larger deduction at tax time. If you use the actual expense method, you can also deduct depreciation on the vehicle. However, you must use the standard mileage rate if you have claimed accelerated depreciation deductions in previous years, such as Section 179 depreciation. (For more on Section 179, see "New Equipment," below.)

If your auto is used for both business and pleasure, only the business portion produces a tax deduction. That means you must keep track of how often you use the vehicle for business, and add it all up at the end of the year. Certainly, if you own just one car or truck, no IRS auditor will let you get away with claiming that 100% of its use is related to your business.