Many countries are asking the people to pay taxes on Bitcoin business, otherwise they are sending notices to the people. We have to be very careful with the governments while dealing with the Bitcoin.
If you are serious about making business through any cryptocurrency, you have to comply with the rules and regulations of your government and also this can help you gain some trust to the investors since you are legally operating.
Yeah you have to pay tax to cash out bitcoin.
I don't pay any taxes yet every time I cash out my holdings, since my country is not yet regulating bitcoin so we can easily convert bitcoin into fiat money without experiencing any problem.