If i sell my bitcoins to a site like coinbase at the end of the year do I need to declare that sale to the vat department and pay the 20% on what i received from coinbase ?
No there is no taxed imposed on that only need to pay is transaction fees. I am from Philippines and i am actively selling my bitcoin because i always need money to buy milk of my kids, also my salary is not enough to sustain our expenses but all of my cash out is only transaction fee is really need it.
I do not think if in other country which bitcoin is already adopted by their government is they already imposed tax in every income of everybody.