The problem is always the same... tracking and making it simple for authorities to later do audits. Their auditing rules ask for things that are somehow hard to deliver, if you're a trader for example....
I mean.. I could be traiding in 10 exchanges... and then cross profits, then change between several coins, and then back to NZD... ONLY when I pass to NZD is the crucial point. Because if the exchange is not simple, things will be messy.
So, I advise you to try to make things simple, and the last and fist transaction to your country FIAT, you should make it on a website that can:
- Export details about that transaction (and reference timestamps, money converted, between which pairs, etc..)
- If the exchange is KYC the better! - it will save you some time at least.
- Wait for all your crypto and issue 1 last transaction to a different address and then convert it to FIAT. This will save you the pain of explaining every account you have (some exchanges have this functionality built in when you trade to FIAT).
- Make your own records... because sometimes exchanges can go down or lose all their information.
If you do not care about the above... and you wish to still pay tax. You can always pay the MAXIMUM tax possible. And save you from any enquiries. As long you can prove the money was indeed yours.
Cheers