Ok. First it depends where you live. Different countries have different rules, but mostly, if you make any money it's going to be taxable income. The question then becomes about thresholds, deductibles and rates.
So, let's assume you're in the US.
How do I file for taxes while earning any crypto currency such as bitcoin, litecoin, DASH, etc?
File your taxes as normal. Any profits you made from Selling BTC (or any coin) is capital gains. You also have to treat spending as selling, since your are bartering your coins for something with a fair value. So, again, calculate any gains. All this goes in 1040 Schedule D.
What if I convert from one virtual currency to another, is there another tax included in the conversion?
While the IRS hasn't confirmed one way or the another, they see a transfer of property as a tax event. Therefore you need to work out any potential gains. Think of it as selling ABC into USD and then buying XYZ with that USD. The alternative would be that you're treating digital currencies as
like-kind exchanges, but they would likely fail this test. Appeal if you get an audit and let me know how it goes
What if mining does become the main source of income, do I still need to file for taxes?
Mining is income. The value of the income is the market value of those mined coins when you received them. Doesn't matter if you keep them, sell them or lose them, you still have that value as ordinary income. When you do come to sell/spend those coins, you use that value as the costs basis to work out capital gains.
I've never declared taxes for my BTCs. Does that get me into trouble?
Doesn't really matter that it's Bitcoin, still tax fraud. You could make the same argument for earning cash and not declaring it.
Will you get into trouble? Yes, if you are caught. The IRS will calculate your taxes for you, which you'll pay with interest, plus any appropriate fines and civil penalties.
With taxes, you are guilty until proven innocent. So KEEP RECORDS. The burden is always on you. If you can't show where and how you got that money, the IRS will tax it at the maximum value.
If you need help calculating your Bitcoin taxes, we've been doing it for everyone for years:
https://bitcoin.taxHere are some top 10 tips about taxation that also might explain a few things.
https://bitcoin.tax/blog/bitcoin-taxes-things-to-remember/