As a disclaimer we want to stress that if you are a professional gambler or if you think you might qualify, you should seek expert legal advice before filing your taxes. If you are a professional sports bettor, casino game player, or poker player, you need to declare your winnings on your T3, T5, and T5013 tax forms which are sent to the Canada Revenue Agency.
You should always have an updated file keeping track of your wins and losses, as well as any business-related expenses that can be deducted against your taxes. Most sports betting sites or online casinos have a history of all your past wagers, but you can keep screenshots on your personal device to be safe. You should also keep receipts for any deposits or withdrawals from in person casinos, or any records of money being transferred to you for large tournament winnings.
If you are a casual gambler, you should still declare your winnings on your tax forms for accountability purposes, but this income won’t be taxed as long as the Canada Revenue Agency doesn’t recognize you as a professional. Any winnings you have from the USA should be declared on your tax forms as well, but you will not be taxed by the Canadian Government.