You pay no tax. Bitcoin is not money it is "magical internet money" it's virtual and piece of code. You alkoeed to trade whenever you like for goods and services. You may accept to be paid in food if you like. You don't pay tax in the food so you won't in the bitcoin. The tax man doesn't have a Bitcoin address so there is nowhere to send it.
Again, this differs from country to country. I know of one country where profits from bitcoin sales are taxed just like profits from any other sales. Whether the tax authority has a bitcoin address is irrelevant, as the profits are in fiat currency and tax is also levied in fiat. Incidentally, if you’re paid in food, you also pay income tax on the value of said food. I expect this applies to many other countries as well, because otherwise employers would likely pay their employees in groceries, fuel, Netflix subscriptions etc. 
