The Financial Crimes Enforcement Network (FinCEN) of the U.S. Treasury Department has issued guidance on banking and other aspects of virtual currency.
This webpage is intended to provide information and links about taxation of virtual currencies in the U.S. and elsewhere, and related information.
In March 2014, the IRS issued Notice 2014-21 and Information Release IR-2014-36, on the income tax treatment of virtual, convertible currency, such as bitcoin. The IRS has ruled that virtual currency is treated as property, rather than currency for tax purposes. That means it needs to be valued when used (such as to buy goods or to compensate an employee) to determine tax consequences. For example, assume Jane purchased X bitcoins last year for $100. Today, she uses that X bitcoin amount to buy clothes worth $120. Jane has a $20 gain on this transaction. Assuming she is an investor or trader in bitcoin (rather than a dealer), this is a capital gain which is taxed at a lower rate for federal income tax purposes than other income such as wages (assuming it is a long-term gain). Jane must keep records to track the basis of all virtual currencies she purchases and identify which ones she uses when she buys something. Basically, Jane is bartering. For more on the tax rules and issues, exchange rates, and other information, see the links below.
Please note - this is not a complete list
21st Century Taxation