Hi.
i didn't traded so much of my crypto for FIAT so i didn't dealt with that question yet.
however i think it's an issue need to be dealt with.
1. do you use accounting services?
2.if so, do you keep documentation of all traded or bought coins?
3. what do you do in cases of profit from ICO's
WHAT SHOULD I DO??
Everything depends on the country in which you live, and how in this country belong to the crypto-currencies. Specify the country, you can be prompted by users who have encountered this.
Yeah because we doesn't know if our country was also like his country too on how the crypto works at their own. I think there are too many kind of things different on every country so when you ask about that then try to ask on your country section that can understand you.