Home Office

While residential rent and mortgage payments are not allowed as a complete deduction, you can deduct the amount of space used in your home as a home office. The room or space must be exclusively used for business to claim this deduction. You can claim a home office deduction even if you claim an additional office space outside the home as long as you regularly use the home office. The amount you can deduct is based on the percentage of the space used as your home office.

Business Miles or Vehicle Costs

The IRS allows business owners to deduct mileage or actual vehicle operations costs. Actual costs include vehicle registration, insurance payments, gas receipts and regular service repairs. Keep track of your invoices, billing statements and receipts to claim this deduction. Alternatively, you can claim business mileage, which is calculated by multiplying the total number of miles you drove throughout the year by the standard mileage rate. As of 2011, the current mileage rate is 51 cents per mile. Use a mileage log to track your business activities throughout the year.

Cell Phone

Whether your cell phone is in your personal or business name, you can write off the cost of using your phone. If the phone is in your name, highlight your cell phone bill to calculate the percentage of calls used for business. The percentage of business calls dialed on your personal phone correlates to the amount of the bill you can deduct on your tax return. If the phone is in your company name, you can deduct the full amount of your bill. However, be sure you have access to another phone. The IRS may disallow the deduction if you use the business phone for personal calls. With no other phone available, it is difficult for you to prove you are not relying on your business phone for personal use.

Medical Expenses

Healthcare costs can be expensive. The IRS gives small business owners a tax break for medical premiums. The full costs of your medical expenses are tax deductible. This includes fees paid to an insurance provider, prescription medicine and co-pays. Keep copies of your hospital bills and co-pay receipts to claim this deduction.