US Casino Winnings as a Canadian: the 30% Taken at the Cage, and the Treaty Refund Most Players Never Claim

The 30% at the cage is real tax, but not necessarily final tax. US-source gambling winnings of a nonresident are FDAP income withheld at 30% — the casino issues Form 1042-S, remits the tax, and the transaction is closed unless the winner does something. What Canadians uniquely can do is Article XXII(3) of the treaty: US-source gambling losses deduct against US-source gambling winnings for the year, so US tax properly applies only to net winnings — and the mechanism for claiming it is a 1040-NR reporting the winnings and losses, computing tax on the net, crediting the 1042-S withholding, and refunding the difference. A player who won US$20,000 (US$6,000 withheld) and lost US$14,000 across the same year owes US tax on US$6,000 and reclaims most of the withholding. The pieces that decide whether the refund is real: an ITIN (Form W-7, typically with the return — casinos also sometimes facilitate); the 1042-S slips (the proof of withholding — every one, kept); and the loss substantiation, which is where claims live or die — win/loss statements from players-card programs, session logs, dated receipts and bank records; the IRS accepts the treaty deduction but audits its evidence like any deduction. Boundary notes: the withholding regime itself exempts certain table-game winnings (blackjack, baccarat, craps, roulette, big-6 wheel are not subject to the withholding rules — cash walks), while slots, keno, bingo above thresholds, poker tournaments, and lotteries withhold; losses deduct only against winnings (net losses refund nothing and carry nowhere); the deduction runs per year, US-source against US-source; and none of this touches the Canadian side, where gambling winnings of a casual player are simply not income — no Canadian tax, and consequently no foreign tax credit for the 30% either, which is exactly why the treaty refund is the only mechanism that ever gets that money back.

Key takeaways

• What withholds: slot and keno wins at reportable levels, bingo, lotteries, poker tournament prizes — 30% for nonresidents, with a 1042-S issued. What doesn't: the listed table games — no withholding on the win itself, whatever its size.
• The treaty refund (Article XXII(3)): US losses offset US winnings within the year; tax recomputes on the net; the excess withholding refunds via a 1040-NR. Net-zero or net-loss years refund the entire 30%.
• The paperwork chain: ITIN (W-7) → 1040-NR for the calendar year → every 1042-S attached → loss evidence held for audit. Refund claims run on the statute for refunds — file within it, and file each year separately.
• Evidence is the whole case: casino win/loss statements (enroll in the players program before playing — retroactive statements are thin), a contemporaneous session log (date, casino, game, amounts), and money-trail records. The deduction is legal; undocumented, it is unclaimable.
• Canada: casual gambling winnings are not taxable income — nothing to report, and no credit path for the US withholding — while a professional gambler is a different analysis on both sides entirely.
• Practical cage notes: carry identification that supports the 1042-S being issued correctly; keep the slips physically; and know that ITIN-holding regulars can sometimes get treaty rates applied in-process — but the refund route works regardless and is the standard path.

Whether the refund is worth the filing

The arithmetic is transparent: 30% of gross winnings recovered down to 30% of net, minus the cost of an ITIN application and a straightforward 1040-NR. A US$1,200 slot win with US$360 withheld and a losing weekend around it refunds a few hundred dollars — worth a self-prepared or modestly assisted claim. Five-figure withholding with a documented losing pattern refunds thousands and is professionally worth doing every year it recurs. The claims that fail are not small ones but naked ones: real losses, no log, no statements — the treaty article stands ready and the evidence never showed up.

Worked example

A Hamilton retiree's 2026 in US casinos: a US$28,000 slot jackpot in Las Vegas (US$8,400 withheld, 1042-S issued), a US$3,000 poker tournament cash in Florida (US$900 withheld), and — per her players-card statements across four properties plus her session log — US$19,500 of losses through the year. Her claim: W-7 filed with a 2026 1040-NR reporting US$31,000 of winnings, the treaty deduction of US$19,500 disclosed under Article XXII(3), tax computed on US$11,500 of net winnings at 30% — US$3,450 — against US$9,300 withheld: a US$5,850 refund. Her tablemate at the jackpot, an occasional visitor with no players card and no records, had a genuinely similar losing year and no claimable evidence of it: his US$8,400 stays in Washington. Same treaty, same article — the refund belonged to the one who logged. On the Canadian side, neither reports anything: the winnings aren't income, which is also why the log, not a credit, was ever the only way home for the 30%.

Official sources

"Losses incurred by a resident of a Contracting State with respect to wagering transactions the gains on which may be taxed in the other Contracting State shall, for the purpose of taxation in that other State, be deductible to the same extent that such losses would be deductible if they were incurred by a resident of that other State." — Canada-United States Tax Convention, Article XXII(3), https://www.canada.ca/en/department-finance/programs/tax-policy/tax-treaties/country/united-states-america-convention-consolidated-1980-1983-1984-1995-1997.html

"You may need to file Form 1040-NR if you: Were a nonresident alien engaged in a trade or business in the United States." — Internal Revenue Service, About Form 1040-NR, https://www.irs.gov/forms-pubs/about-form-1040-nr

Practitioner note

Casino withholding is the most refundable tax Canadians routinely abandon, and the treaty article that returns it asks only for arithmetic and evidence. Our advice fits on a cocktail napkin: players card at every property, a session log on your phone, keep every 1042-S, and file the 1040-NR each winning year — because the deduction is guaranteed by treaty and the refund is guaranteed by nothing except your records.

See also: For why every US bank and broker asks Canadians for a W-8BEN, see why every US bank and broker asks Canadians for a W-8BEN; and browse every cross-border tax topic guide, organized by situation.

Next step

Fairlight prepares the gambling refund claim — ITIN setup, the annual 1040-NR with the Article XXII(3) computation, and the evidence system that survives review. See cross-border pricing or book a call.