- The IRS allows home office deduction only for the business use of a part of your home. It qualifies as business use if you use it exclusively for business -- to do office work or meet customers, for example. If you divide your office between business and non-business use, it doesn't qualify for a deduction. If you regularly do office work in your bedroom, for example, it is not an office for tax purposes.
- To calculate the deduction, total your expenses for the upkeep of your home. Next, determine the total square footage of your home, and compare that with the total square footage of your home office. You may deduct that percentage of your total upkeep expenses that is equivalent of the percentage of square footage your home office occupies compared to the size of your entire home. For example, if your office is 10 percent of the total size of your home, you may deduct 10 percent of your total home upkeep expenses from your taxable income.
- If you are self-employed, file IRS Form 8829, and insert the amount of your deduction on line 30 of Form 1040. If you are an employee, include your home office deduction as a miscellaneous business expense on Schedule A of Form 1040. If you are an employee and you take the standard deduction instead of itemizing your deductions, you cannot use the home office deduction, with one exception -- count yourself as self-employed for the purpose of this deduction if your employer requires you to work at home, rather than simply allows you to.
- Common pitfalls in applying the home office deduction include deducting upkeep expenses for dual-purpose areas, and overestimating the size of your office space. You might also fail to claim a deduction you are entitled to -- for example, you are entitled to write off upkeep expenses for a detached tool shed where you store business inventory