我给你总结个大意：是收入就要交税。这是大原则。怎么交税，交多少，得看美国浩如烟海的税法。
http://www.msnbc.msn.com/id/11658852/ns/business-answer_desk/
I have a very simple question but one in which no one seems to have an answer. I made $2,600 profit on eBay selling old items last year. Do I need to report that income on my tax return? … Ebay does not send out 1099's, so I ask: how would the federal government know what I made selling items on Ebay? They would not. The other point some people have mentioned was it a business or a hobby selling items on Ebay? For me it was a hobby. I did not buy and resell items at a higher price. My tax accountant advised me not to report the extra income. I am interested to hear your thoughts on the issue and what the IRS thinks? Michael, Randallstown, MD
It is against the law not to report all income to the IRS.
It’s also true that billions of dollars in income go unreported every year. The exact amount, for obvious reasons, is tough to pin down. Much of this unreported income doesn't hit the IRS radar because it comes from sources that don't independently report it -- like wages paid by employers or dividend and interest income paid by banks and investment firms. To help you stay on the right side of the law, the IRS has come up with all sorts of ways to report this miscellaneous income. If you want to call your eBay venture a hobby, for example, you can only do this as long as you're not pursuing the hobby with the intention of making money. (One test requires that you make no profit from your hobby in two of five consecutive years.) If you do report this as hobby income, you can deduct hobby expenses from your that income. But you can’t use hobby losses to offset other, non-hobby income.
