Polymarket Taxes in Canada: Windfall, Capital Gain or Business Income?

The CRA has not published guidance on Polymarket or any other prediction market, so Canadian tax treatment is unsettled. There are three ways profits could be characterised. A casual punter's winnings could be a non-taxable windfall, as gambling winnings usually are. Profits could be capital gains, with half included in income. Or frequent, systematic trading could be business income, which is fully taxable. Which one applies depends on facts like frequency, organisation and intent, and it changes your tax bill a great deal.

OddsFile is software, not tax advice. The CRA has not issued guidance on prediction markets, and no Canadian court has ruled on them. This article lays out the possible treatments and the sources; a Canadian tax professional can tell you which position fits your facts.

Availability: close-only in four provinces

Polymarket's geoblocking documentation lists Ontario, British Columbia, Alberta and Quebec as close-only. Residents there can close existing positions but cannot open new ones. Other provinces are not on the list today. Whether you can access a platform is a regulatory question, not a tax one. Profits and losses you have actually made still need to be dealt with on your return.

The three possible characterisations

1. Windfall (not taxable)

In Canada, recreational gambling winnings are generally not income. Courts treat them as windfalls because there is no "source of income" in the tax sense. The flip side is that recreational gambling losses are not deductible. If a Polymarket position is a bet and you are a casual participant, this view says the result is outside the tax system.

Two things work against relying on it. First, Polymarket positions are tokens that you can buy and sell before the event resolves. That looks more like trading property than placing a bet. Second, the more systematic your activity is (arbitrage, bots, many trades a day), the stronger the CRA's case that you have a source of income.

2. Capital gains (50% included)

The CRA's crypto guidance, Reporting income from crypto-asset transactions, says that if your activity is not a business, "you must include half of your capital gains (known as taxable capital gains) in your income for the year." Half of capital losses (allowable capital losses) can only offset taxable capital gains. Unused amounts carry back three years or forward indefinitely. The proposal to raise the inclusion rate to two-thirds was cancelled in March 2025, so 50% still applies.

Under this view, each disposal is a capital event: spending USDC to buy outcome shares, selling shares, redeeming winners and converting USDC to CAD. Capital gains and losses go on Schedule 3 of your T1 return. The CRA's capital gains guide is T4037.

3. Business income (100% included)

The same CRA page lists signs that crypto activity is a business, including "frequency of transactions", short holding periods, knowledge of the markets, time spent studying them, and financing with debt. Prediction-market trading is short-term by design: many markets resolve within days or hours. Business income is fully taxable and reported on Form T2125. Business losses can offset other income.

Comparison table

Cost base: averaging, not FIFO

Canada uses an adjusted cost base (ACB) that averages the cost of identical properties. The general rule is in the CRA's capital gains guide T4037. Each Polymarket outcome token is its own property, so each market and side gets its own average cost. USDC is a separate pool too. US-style FIFO reports, including any generated for American users, don't carry over directly. The figures must be worked out in CAD using the exchange rate on each transaction date. The CRA's valuation page asks you to use a reasonable valuation method and apply it consistently.

The superficial loss rule

Canada's superficial loss rule denies a capital loss if you, or an affiliated person, acquire identical property within 30 days before or after the sale and still hold it 30 days after. The denied loss is added to the cost of the repurchased property. Practitioners generally apply this rule to identical crypto-assets held as capital property. Whether it matters for prediction markets is less clear. Two positions on the same Polymarket market and side are identical, but a "YES" on a different market is not. If you sell a position at a loss and buy back into the same outcome within 30 days, ask your adviser about it. The rule does not apply to business inventory.

Worked example

Assume USD/CAD = 1.37 throughout, a 30% combined marginal rate, and these 2025 results:

In a losing year the picture flips. A net CAD $3,000 loss is worth nothing as a windfall. As a capital loss, it gives a $1,500 allowable loss that can only offset taxable capital gains, carried back or forward. As a business loss, the full $3,000 offsets other income. A characterisation can't be switched year to year to suit you. Facts and consistency matter, and the CRA can reassess.

What about Kalshi or other US platforms?

Kalshi is a CFTC-regulated US exchange that is mainly open to US residents. The same three-way analysis applies to any event-contract platform a Canadian resident uses. The difference is that fiat platforms don't add the extra USDC disposals. US forms such as a Kalshi P&L statement or a 1099 are not Canadian tax documents. You still compute everything in CAD under Canadian rules. For background on US reporting, see Kalshi taxes and the 1099.

Records to keep

• Every trade, redemption, deposit and withdrawal, with timestamps.
• The CAD value of each transaction (a Bank of Canada daily rate is a common, defensible source).
• Wallet addresses and links between them. If you use several wallets, see multiple wallets.
• Losing positions you never redeemed. They still went to zero. See unredeemed losing positions.

FAQ

Is Polymarket taxable in Canada?

Possibly. The CRA has not ruled. Casual, recreational use may produce non-taxable windfalls. Investment-style use points to capital gains with 50% included. Frequent, systematic trading points to fully taxable business income.

How is Polymarket taxed in Canada if I trade a lot?

High frequency, short holding periods and organised methods are the business-income signs the CRA lists for crypto. Under that view, 100% of net profit is income, reported on T2125, and losses can offset other income.

Can I deduct Polymarket losses in Canada?

Not under the windfall view. Under the capital view, half of a loss is an allowable capital loss usable only against taxable capital gains. Under the business view, the loss can offset other income.

Do I have to report USDC conversions?

The CRA treats crypto-to-crypto and crypto-to-fiat exchanges as dispositions. USDC is usually close to USD 1, but in CAD terms exchange-rate moves can create small gains or losses.

Do US rules like the 90% gambling-loss cap apply to me?

No. That is a US federal rule. It matters only if you also file US returns. See the 2026 90% limit.

Start with accurate P&L

Every characterisation needs the same raw material: per-market results, fees and dates. Run the free OddsFile check: paste a Polymarket address and see each market's profit and loss, with losing positions you never redeemed included. CAD and ACB reports are planned. Today's export gives your accountant a complete transaction trail.

Related reading: Polymarket taxes: the complete guide (US), Polymarket tax in the UK, Polymarket tax in Australia.