As Tax Agents and accountants we get asked this quite often. Some countries are taxed on their gambling winnings. Australia is the lucky country and the income derived from these activities is not taxable for three main reasons:-
1) It’s generally not considered a profession. It’s a hobby or recreational activity.
2) Gambling is generally seen to have a large element of luck in it. Most would be gamblers would lose money rather than win. For that reason the ATO would not be prepared to deduct losses from gambling.
3) The government taxes the gambling operators instead. Also the government will charge the operators to become officially licensed Have a great day watching the race that stops the nation and gamble responsibly