If you work out of your home and your home is your principal place of business, you can generally deduct the cost of traveling from home to any business destination. This is true whether the destination is another regular place of business, a temporary place of business (such as a client or project location), or a destination such as a bank, post office, supplier, etc.
Whether your home is your principal place of business is determined under the
same standards that apply to home
office deductions. If your home doesn't qualify as your principal place of
business, you must follow the general
rules in determining whether a particular car trip is sufficiently
business-related to be deductible.