what i understand it doesn't need to be sold back to Fiat but to...

what i understand it doesn't need to be sold back to Fiat but to anyone with the official rates from the reputable exchanges at the time of the transaction

""You need to keep the following records for bitcoin transactions:
the date of the transactions
the amount in Australian dollars (which can be taken from a reputable online exchange)
what the transaction was for
who the other party was (even if it’s just their bitcoin address)."""