How to prove gambling losses on your taxes
The IRS lets you deduct gambling losses against winnings, but only if you can prove them. Here is what counts as proof, how to keep the diary, and what the 2026 90 percent rule does to a break-even year.
Published 2026-10-27 · Updated 2026-11-04
Not tax advice. This page explains the rules in plain language so you know what records to keep. Tax law changes and your situation is specific to you. Talk to a CPA or enrolled agent before you file.
The rules in one paragraph
All gambling winnings are taxable income, whether or not you got a Form W-2G. Losses are deductible only if you itemize on Schedule A, only up to the amount of your winnings, and, starting with the 2026 tax year, only up to 90 percent of the losses themselves. You cannot net losses against winnings on the income line; winnings go in as income, losses go in as a deduction. And the deduction survives an audit only if you can substantiate it. That last part is where most people fall down.
What the diary must contain
IRS Publication 529 is specific. Keep "an accurate diary or similar record" of your winnings and losses showing, for each session:
- The date and type of your specific wager or wagering activity.
- The name and address or location of the gambling establishment.
- The names of other persons present with you at the establishment.
- The amount(s) you won or lost.
The word that matters is contemporaneous. A diary reconstructed in March from bank statements is weaker than one written the night of each session, and auditors know the difference. That is the whole case for logging on your phone as you leave the table.
What counts as proof, ranked
| Evidence | Weight | Why |
|---|---|---|
| Your own contemporaneous session log | Strongest | It is what Publication 529 asks for, and it covers unrated play. |
| Forms W-2G and 5754 | Strong, for winnings | Issued by the casino; the IRS already has a copy. |
| Casino win/loss statements | Supporting | Estimates from players club tracking, usually with a disclaimer. Good corroboration, poor sole evidence. |
| ATM withdrawals, markers, credit records, cashed checks | Supporting | Shows money went in; does not show how much came out. |
| Tickets, receipts, payment slips | Supporting | Useful for slots, sports and racing; blackjack generates few. |
| Memory and round numbers | Weakest | "About $500 a trip" is where deductions go to die. |
Sessions, not hands
You are not expected to record every hand. Casual gamblers measure a session: one continuous period of play at one establishment, the amount you started with against the amount you left with. Play blackjack for three hours at one casino, buy in for $1,000, colour up $1,340: that session is a $340 win. Lose $600 the next night: that is a $600 loss. Report the sum of winning sessions as income and the sum of losing sessions as the deduction. Professional gamblers who file Schedule C have different rules and should work with a preparer who knows them.
The 2026 90 percent limit
The One Big Beautiful Bill Act (Public Law 119-21, signed July 4, 2025) amended the wagering loss rule for tax years beginning after December 31, 2025. The deduction is now limited to 90 percent of losses, and still cannot exceed winnings. The effect is sharpest for high-volume players who roughly break even:
| Scenario | Winning sessions | Losing sessions | Deduction | Taxable |
|---|---|---|---|---|
| Weekend player, 2026 | $8,000 | $9,000 | $8,000 (capped at winnings) | $0 |
| Regular, break-even | $60,000 | $60,000 | $54,000 | $6,000 |
| Regular, net loser | $60,000 | $70,000 | $60,000 (capped at winnings) | $0 |
| Winning player | $120,000 | $80,000 | $72,000 | $48,000 |
In the net-loser row, 90 percent of $70,000 is $63,000, but the deduction is still capped at the $60,000 won. Notice the middle rows: the cap bites when losses are close to winnings. Repeal bills have been introduced; as of this writing the limit stands for 2026. State rules differ, and several states allow no gambling loss deduction at all.
Five mistakes that lose the deduction
- Relying on the win/loss statement alone. It is an estimate with a disclaimer. Pair it with your diary.
- Netting on the income line. Winnings are income; losses are a Schedule A deduction. Netting invites a mismatch with the W-2Gs the IRS already holds.
- Taking the standard deduction and the loss. You cannot. The loss deduction only exists if you itemize.
- Reconstructing in April. Dates, places and amounts from memory read like guesses because they are.
- Deducting more than you won. Even before 2026, losses were capped at winnings. Now it is the lower of winnings and 90 percent of losses.
Keeping the record without the work
A session log is four fields and a timestamp. Blackjack Logger, free on iPhone and Android, captures them in about ten seconds as you leave the table: result, casino, date and time, hours, with an optional note for anyone you played with. At year end, Settings → Backup & export writes a CSV with one row per session, which is the diary Publication 529 describes in a form your preparer can use. Nothing is uploaded; the record stays on your phone, behind Face ID if you want it. How the gambling log works.
The diary is easy on the day and impossible in April.
Free on iPhone and Android. No ads, no subscription.
Sources
- IRS, Topic No. 419, Gambling income and losses
- IRS, Publication 529, Miscellaneous Deductions
- IRS, Instructions for Schedule A
- Public Law 119-21, One Big Beautiful Bill Act, section 70114
FAQ
Can you claim gambling losses on your taxes?
Yes, as an itemized deduction on Schedule A, up to the amount of your gambling winnings. From the 2026 tax year the deduction is also limited to 90 percent of your losses. You cannot deduct losses if you take the standard deduction.
How do I prove gambling losses to the IRS?
With a contemporaneous diary showing the date and type of wager, the establishment, the people with you and the amounts won or lost, backed by W-2Gs, casino win/loss statements, bank and ATM records and receipts. The diary is the primary record; the rest corroborates it.
Is a casino win/loss statement enough proof?
On its own, usually not. It is an estimate of rated play with a disclaimer. Use it to support your own log, not replace it.
Do I have to report winnings if I had a net loss for the year?
Yes. Winnings are reported as income regardless of your net result. Losses are a separate deduction, and only if you itemize.
What is the 90 percent gambling loss rule?
For tax years starting in 2026, deductible gambling losses are limited to 90 percent of actual losses, and still capped at winnings. A break-even year can therefore produce taxable gambling income.
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