IMPORTANT DISCLAIMER: I am not a tax professional. If you have significant tax questions, seek the help of a certified professional accountant.
The general rule is that if there is something you need to have for your work, that you yourself have paid for and are not being reimbursed for, then you can claim that cost as a deduction. If you are getting personal use out of your purchase, then you can usually claim a fraction of the cost that reflects the fraction of business use you put it to. For example, if you have a cell phone that you use 50% for work and 50% for home, then you can claim 50% of the cost of the cell phone bill as a work-related expense.
Bear in mind that in the United States, your standard deduction may be greater than what you can get by itemizing all of your work expenses; unless you have a lot of these expenses, or other large deductions (such has health care costs or mortgage interest), it's usually not worth the effort of itemizing them.
Here are some specific things you
cannot claim as work expenses:
- Regular clothes that you wear to work. Uniforms that are work-specific you can claim; business suits and office attire, you can't.
- The cost of commuting to work. You can claim vehicle-related expenses if you are using your own car for work purposes, and you are not being reimbursed for it.
- Expenses you incurred in paying for these expenses. For example, credit card interest, ATM fees, check fees, etc.
- The cost of food you eat while at work. Business entertainment (lunches with clients, etc) are a different matter, and may be deductable if they are reasonable expenses that are not reimbursed.