Same in most parts of europe.
BTC are not money legally

So...
...I operate a mining farm, all expenses are expenses

Nice. Recudeds my tax income.
...all sold BTC are income. Good. I need some - dont wan to run at a loss

...all KEPT btc are inventory - and unless I get really large otherwise, this is not reported, as I report profit/loss, not goods are hand

So, I sell some, to pay and expand, and keep some fo which I dont pay income tax until I sell them and get "real" currencyl.
Real and not currency totally in the definition of the law here
