What factors does the CRA typically look at when auditing someone who reports gambling winnings?

Canada's tax treatment of gambling winnings is genuinely misunderstood — and the confusion isn't surprising, because the default rule and the exception look similar on the surface but lead to very different tax outcomes.

The default: winnings are not income. Lottery winnings of any amount are generally not taxable, unless the prize can be considered income from employment, a business, or property. The same logic applies to casino and online gambling wins for the typical recreational player. Lottery and certain other winnings are non-taxable in Canada — however, if a taxpayer is in the business of gambling, the proceeds and losses are considered for income tax purposes. So the entire audit question pivots on one thing: are you a recreational player, or are you effectively running a gambling business?

How the CRA decides which side of that line you're on

Whether a taxpayer's activities constitute carrying on a gambling business is a question of fact, determined only by examining all the circumstances and the taxpayer's entire course of conduct. Although no single factor is conclusive, the CRA considers: the degree of organization present in pursuing the activity; the existence of special knowledge or inside information that reduces the element of chance; and the taxpayer's intention — gambling for pleasure versus gambling for profit as a means of livelihood.

That last point is trickier than it sounds. Gambling is always undertaken in pursuit of profit — but as one court put it, the intention to win money "is shared by all who gamble," and the mere presence of that intention does not lead to the conclusion that all who gamble frequently are carrying on a business. In practice, the bar is high. Exceptional cases where gambling has been held to be taxable relate to taxpayers who applied inside information, knowledge, and skill to their activities.

The windfall test. On the other side of the ledger, the CRA has a formal checklist for what makes a receipt a non-taxable windfall. Indicators include: the taxpayer made no organized effort to receive the payment; had no customary or specific expectation of it; had no reason to expect it would recur; and the payment was not from a customary source of income for the taxpayer. A recreational player at a licensed Ontario online casino generally ticks all of those boxes.

What auditors actually look at in practice. When gambling winnings surface during an audit — often because large deposits appear in a bank account — auditors consider whether non-taxable winnings explain the taxpayer's accumulation of assets, lifestyle, and deposits to personal bank accounts. If the taxpayer claims gambling winnings as the source of funds, auditors request documentation of all winnings and losses. Auditors also note that a taxpayer may readily recall wins but need prompting to recall losses — so the completeness of your records matters. If there is genuine doubt about the receipt of lottery and other winnings, the benefit of the doubt must be decided in the taxpayer's favour.

For players on Ontario's regulated online platforms, transaction history is readily available through the operator's account portal — deposit records, withdrawal records, session history. Keeping that data organized is the simplest thing you can do to document the recreational nature of your play, should you ever need to. The CRA's broader audit toolkit also includes the net worth method: the net worth method is the most common indirect verification of income used by the CRA, and auditors consider changes in assets and liabilities, personal spending, and non-taxable sources of income — including lottery winnings — as part of that analysis.

One practical note: income earned on gambling winnings is taxable — for example, any interest you earn by investing those winnings must be reported. Winning itself isn't the taxable event for most players; what you do with the money afterward can be.

Tax law here is genuinely complex and fact-specific. If you're playing regularly on licensed Ontario sites and have questions about your own situation, a tax professional is the right call — not a casino information site. And if gambling ever starts to feel less like leisure and more like something you need to manage, ConnexOntario (1-866-531-2600) is there. The full CRA guidance lives in Income Tax Folio S3-F9-C1 on canada.ca, which is worth reading directly.