The Internal Revenue Service (IRS) requires that our writing expenses be ordinary and necessary in order for them to be acceptable. An ordinary expense is defined as common and accepted in our profession. A necessary expense means we need to spend this money in order to operate the business. The expenses must not be considered extravagant. They must be an essential part of doing business as a writer. It is important to differentiate between personal expenses and business expenses.
Writers are able to realize some unique deductions which may be considered personal for other taxpayers. For example, a book on the history of New Mexico used for researching my fiction manuscript based in that state could be deductible as a writer.
Check out my book, Bookkeeping Basics for Freelance Writers, to learn more about deductible expenses and how to reduce the income taxes you pay as a writer. You can read about it on my web site and on Amazon.com.