Question for anybody who has sold articles to magazines or knows the relevant tax law. Say I write an article or articles about work I've done on my experimental airplane and get paid for it. Not much, a few hundred dollars each time. The publisher sends me a 1099. I'm supposed to report that on Schedule C. What can I deduct against that so I don't owe taxes on it? Any expenses related to the plane (like hangar rent, flying time, maintenance expenses, fuel, insurance, etc.)? Those are a lot more than I got paid. Or just the expenses directly related to the work I'm writing about (still more than the income)? If the latter, what if I incurred those expenses the year before I actually got paid? I've read all about taxes and hobby businesses, but nothing I've read seems to cover this. I'm not looking to show a loss and reduce the taxable income from my day job (though it would be nice, I suppose, if legal), just to avoid paying taxes on the writing income. But if I deduct, say, several thousand of hangar rent, etc., against a couple hundred of income and show that as a loss, that doesn't sound reasonable (especially if I do it for several years) and would likely trigger an audit... there doesn't seem to be a "if less than zero, enter zero" option as there is in other places in tax forms.