Do I need to keep records of my online casino wins and losses in case the CRA ever asks about them?

The short answer for most Ontario players is: you're not legally required to keep records specifically for tax purposes, because casual gambling winnings are generally not taxable in Canada. But "generally" carries some real weight here, and understanding the nuance is genuinely useful.

The baseline: casual gambling wins aren't income

Lottery and certain other winnings are non-taxable in Canada — however, if the taxpayer is in the business of gambling, the proceeds and losses are considered for income tax purposes. The CRA's own guidance confirms this for recreational players: lottery winnings of any amount are not reported or taxed, unless the prize can be considered income from employment, a business or property, or a prize for achievement. So if you're playing slots or blackjack on a registered Ontario iGaming site as a pastime, your wins land in that non-taxable category and you don't owe the CRA a thing on them — and therefore have no filing obligation that would demand records.

Even the CRA's own audit manual reinforces that where there is genuine doubt about the source of funds, the benefit of the doubt must be decided in the taxpayer's favour.

That said, the line between "recreational player" and "gambling business" is where things get complicated. The issue of whether a taxpayer's activities are such that they can be considered to be carrying on a gambling business is a question of fact that can be determined only by an examination of all the circumstances and the taxpayer's entire course of conduct. The CRA looks at factors like the degree of organization in the pursuit of the activity, the existence of special knowledge or inside information that reduces the element of chance, the taxpayer's intention to gamble for pleasure versus profit as a means of gaining a livelihood, and the extent of the gambling activities, including the number and frequency of bets.

Importantly, just playing a lot doesn't automatically make you a business. Gambling — even regular, frequent and systematic gambling — is something that by its nature is not generally regarded as a commercial activity except under very exceptional circumstances. There are some exceptional cases where gambling activities have been held to be taxable, but these relate to taxpayers who applied inside information, knowledge and skill to their activities. The typical recreational casino player in Ontario is nowhere near that territory.

Where records do become practically important is if the CRA ever reviews your bank account and sees large, unexplained deposits. Non-taxable lottery and other winnings may arise as an issue if the CRA is attempting to identify the source of funds to support a taxpayer's accumulation of assets, lifestyle, and deposits to personal bank accounts — and if the taxpayer states that the source of funds is lottery or other winnings, the CRA will request documentation for all winnings and losses. In other words, the records aren't required upfront — but if you're ever asked to explain where money came from, being able to point to your account history on a regulated platform becomes very helpful very quickly.

This is one practical advantage of playing on Ontario's regulated iGaming market. Because operators registered with the AGCO and iGaming Ontario maintain verified player accounts with full transaction histories, you can typically retrieve your own deposit, withdrawal, and session records directly from your account. That's a far better position than trying to reconstruct activity after the fact.

One final point worth flagging: income earned on gambling winnings is taxable. For example, any interest you earn when you invest those winnings must be reported on your return. The windfall itself may be tax-free; what you do with it afterward may not be.

Because tax law in this area turns on individual facts and circumstances, anyone with a complex situation — high-volume play, significant deposits, or activity that starts to look systematic — should speak with a Canadian tax professional rather than rely on general guidance. For responsible gambling support in Ontario, ConnexOntario is available at 1-866-531-2600.