USAToday featured a question and answer article related on taxes, specifically the exclusivity requirement of home office deductions.

Q: I have a small business where I see patients in a clinic but do my billing, report writing and other administrative activities in a small office I built in my basement. My concern regards the exclusivity requirement of the home office deduction. I cannot say that I don't occasionally surf the net on my office PC, but for the most part, it is my home office, where my business is managed. No one else in my family ever even enters the room. When the IRS says "exclusive," how flexible are they with that term, if at all?

The answer of Patricia Thompson, an AICPA member, is as follows:

Taxpayers are eligible for a home office deduction if the space is used exclusively and regularly as a principal place of business, as a place to meet or deal with clients and customers in the normal course of business, or "in connection with" the business if the space is a separate structure from the residence.

The benefit of a home office deduction allows the taxpayer to expense the business portion of home related expenses such as mortgage interest, real estate taxes, insurance, repairs, utility costs and depreciation.

There are exceptions to the exclusive use requirement if you use part of your home for the storage of inventory or product samples or if you use part of your home as a daycare facility.

Your question relates to the exclusive use requirement. The exclusive use requirement relating to a home office seems to be an all or nothing standard and can be very restrictive. Any personal use of the home office will disqualify you from taking a home office deduction.