The tax code doesn’t address the question of who lives in the home or apartment. There are only two requirements for being able to deduct your home office space to run your small business. It must be used both regularly and exclusively for business purposes. Exclusively means that it can’t be used for any other purpose during the year. It must be your principal place of business if you have more than one location for this business. If you and your roommates can agree on a space to reserve for your business use only, measure the space and determine what percentage of your home or apartment it is. If the space is less than 300 square feet, you may be able to use the simplified method instead of using the more complicated Form 8829. Just multiply the square footage by $5 and include it on your Schedule C.