The Internal Revenue Service issued a reminder Friday to taxpayers that they need to report any income from gains they get from virtual currency transactions on their tax returns.

The move comes after the IRS forced one of the largest cryptocurrency exchanges in the world, Coinbase, to send information on 13,000 of its users to the IRS last month after a legal battle involving the use of “John Doe” summonses.  That mean if you have engaged in transactions involving Bitcoin, Ethereum, and other digital currencies, you are expected to report those gains to the IRS.

The IRS pointed out that virtual currency transactions are taxable by law, similar to transactions involving other personal property.  The IRS issued guidance in 2014 in Notice 2014-21 spelling out the agency’s position on digital currency transactions for taxpayers and tax preparers.

The IRS warned Friday that taxpayers who do not properly report the income tax consequences of their cryptocurrency transactions fact the possibility of tax audits, and could even be liable for penalty and interest charges when appropriate.

Under Notice 2014-21, virtual currency is treated as property for federal tax purposes, so the general principles that apply to property transactions also apply to the 1,500 or so known varieties of cryptocurrency.  That means reporting payments made with virtual currency.

Payments made to independent contractors and other service providers are also taxable and self-employment tax rules apply. Have you been trading in cryptocurrency?