How to Prove the Source of Gambling Winnings

Why proof of source matters for gamblers

Money that appears in your account from a win can look, to a bank or a tax office, like money from anywhere. The way to show it came from gambling is the paperwork the win itself generates: the ticket, the receipt, the claim record, the statement. Different places produce different paperwork, and knowing which piece matters saves you a difficult conversation later.

In China, the rule is unusually blunt: the winning ticket is the only voucher for redemption of a sports lottery prize. No ticket, no prize, and no proof. For single-bet winnings over CNY 10,000, the sports lottery institution withholds and remits personal income tax on your behalf, so the redemption itself creates a tax record³.

Vietnam shows the other side of proof. Under Circular 111/2013/TT-BTC, when one prize has multiple winners, the taxable income is divided among them, but only if the winners present legal proof of the split. Without it, the whole prize is counted as one individual's income, and multiple prizes won in one game are taxed on their total value⁴. The proof is not a formality; it changes the tax.

Even collecting a prize creates identity records. In Japan, claiming a sports lottery prize at a shop requires a document that proves who you are, such as a driver's license or My Number card⁵. In India, racecourse bookmakers are required to record the names and addresses of backers making transactions of Rs 5,000 or more, and of anyone winning Rs 10,000 or more⁶. In other words, several points in the gambling process already generate a record that ties you to a specific win. Your job is to keep it.

If you want the wider picture of how wins are taxed country by country, see our guide to tax on gambling winnings in Asia.

What to note for each payout: date, venue, race and amounts

Japan's National Tax Agency is refreshingly specific about what a player should write down for each payout from public racing, meaning horse racing, keirin, auto racing and boat racing. Three items:

1. The date, venue and race of the meeting
2. The amount received as the payout
3. The amount wagered on that payout¹

The reason is tax. A payout from public racing can require a final tax return, and the taxable amount is calculated as the payout minus the cost of the winning tickets, minus a special deduction of up to JPY 500,000⁷. Without your own note of what you bet, you cannot reconstruct that calculation. The same three-item note is what the Agency's guidance repeats for anyone who received payouts during the year⁸.

The betting materials themselves help.

Fixed-odds betting gives you a second anchor. Under Hong Kong's fixed odds rules, the odds recorded in the operator's official records for each bet are the odds used to calculate the payout, and for fixed odds bets the payout for each winning bet is rounded to the nearest 10 cents¹². The recorded odds cannot be changed after the bet is struck, so a screenshot or a printed slip is stable evidence.

Some betting systems build the record for you. A keirin mark card has you mark the race venue, bet type, race number, prediction, amount and cancellation, so the card itself carries the race details¹³. On the bet inquiry screen at keirin venues, pressing the results button switches the display to your selections, the payout amounts and the race results, and winning races show the payout in red¹⁴. Photograph that screen and you have the date, race and amount in one image.

Collecting prizes in a way that leaves a record

How you claim a prize determines what paper you walk away with. The strongest records come from channels that log the transaction against your name or a ticket number.

Japan's sports lottery is a good model. For tickets bought at a shop, you check results on the official site by selecting the lottery type and draw number, entering the 12-digit reference number printed on the ticket, and clicking the results button¹⁵. For BIG tickets bought online, you log in to Club toto, click the purchase history and winning check menu on the top page, then select detail check, where you can filter by product, purchase period and winning result¹⁶. The same flow works for non-members checking store-bought tickets: top page, lottery type, draw number, reference number, results¹⁷. Members who bought on the official site do not even need the reference number; the member menu lists purchase history and winnings¹⁵.

Claim periods also matter, because a prize you can no longer claim is not evidence of anything. Japan's sports lottery publishes explicit windows: for one WINNER single-match draw, refunds could be claimed for one year from April 7, 2026 to April 6, 2027¹⁸, and for another, from February 10, 2026 to February 9, 2027¹⁹. Claim inside the window and the claim record exists; miss it and the ticket is just paper.

Racecourse payout windows have their own rhythm. At Nagoya, payout business runs from the first race selling start time until the final race payout end on race days, and on off days payouts are handled only when off-course sales of other districts are being held²⁰. JRA notes that refunds can in some cases be subject to income tax and inhabitant tax, and that confirmation may be requested, pointing players to the National Tax Agency's pages²¹. Local racing authorities warn in the same breath that payouts may be taxable and a final return may be required²². The practical habit is the same everywhere: keep the ticket, note the race, and keep whatever receipt the payout window gives you.

For the tax side of claiming prizes across Asia, see when are winnings taxed.

TDS on net winnings in India: 30% at withdrawal or year end

India handles the proof problem differently: the operator does the record keeping for you. All real money gaming apps are required to deduct tax at 30% on your net winnings, at the time of withdrawal or on 31 March, the end of the financial year². Net winnings means withdrawals minus deposits.

The operator's own examples show how the arithmetic works:

• Deposit INR 2,000, withdraw INR 3,000. Net winnings are INR 1,000, tax is 30%, so INR 300 is deducted and the payout is INR 2,700².
• Deposit INR 2,000, withdraw INR 2,000. Net winnings are zero, no tax is deducted, and the payout is INR 2,000².
• Total withdrawals INR 9,000 against total deposits INR 8,000, with INR 300 of tax already deducted on an earlier withdrawal. Total net winnings are INR 1,000, tax due is INR 300, but since INR 300 was already deducted, nothing further is taken and the payout is INR 4,000².

That last example answers the question players ask most: no, the same winnings are not taxed twice. If tax has been deducted on positive net winnings at a withdrawal, it will not be deducted again on those same winnings on 31 March².

For the broader withholding picture across Asia, see withholding tax on winnings.

How the TDS calculation resets on 1 April

The TDS clock runs on India's financial year. Starting 1 April 2025, all TDS calculations are reset². Anything left in your account on 31 March 2025 is treated as a withdrawal and taxed as such, and the remainder is carried forward into the new year.

The operator's year-end example spells it out. Suppose your net winnings at year end are INR 500, so the 30% tax is INR 150. If INR 100 has already been deducted during the year, the remaining INR 50 is deducted from your closing account balance of INR 1,000, leaving INR 950 carried into the new financial year².

The practical point for record keeping: your statements should let you reconstruct the year as a whole, deposits and withdrawals from 1 April to 31 March, not just the latest transaction. The year-end deduction is calculated on the full year's net position.

Checking your tax calculation on the withdrawal page

You do not have to take the app's word for the deduction. The tax calculation can be checked on the withdrawal page of the app². Before you confirm a withdrawal, the page shows how the tax on your net winnings was worked out.

It is worth checking against your own records, because the calculation is simple enough to verify: total withdrawals minus total deposits, times 30%, minus tax already deducted. If your own deposit and withdrawal history does not match what the page shows, that is the moment to raise it with the operator's support, while the transactions are still fresh.

Tax refunds for players with negative net winnings

Losses can come back to you in India. If net winnings are negative at the end of the financial year, 31 March 2026, players may be eligible for a tax refund, claimable while filing their tax return². The refund route is the income tax return, not the gaming app, so the documents that matter are your own statements plus the tax deduction records.

Other countries treat losses and wins differently, which changes what proof is worth keeping:

• In Singapore, winnings from betting or lottery do not need to be declared in the income tax return at all²³, so the record is mainly for your bank's benefit.
• In South Korea, other income tax on race payouts depends on the size of the refund and the payout rate: refunds of KRW 100,100 to 2,000,000 per bet at a payout rate over 100 times are taxed, with a payment statement prepared when the refund is KRW 2,000,100 or more per bet²⁴. That payment statement is exactly the kind of document worth filing away.
• In Japan, no income tax is imposed on refunds under the Act on Sports Promotion Voting²⁵, though racing payouts follow the separate temporary-income rules described earlier.
• In Vietnam, from July 1, 2026, winnings from betting are taxable under the Personal Income Tax Law, while casino winnings are exempt²⁶. For betting wins, only the portion of each prize that crosses VND 20 million is taxed, and that threshold applies to each win separately²⁶.

For the mechanics of claiming back tax that was withheld, see getting back tax withheld on winnings.

Identity checks when you sign up or cash out

The other half of proving source is proving who you are, because a receipt in someone else's name proves nothing about your money. Identity checks now happen at both ends of the gambling process in much of Asia.

In India, KYC verification is mandatory for the creation of an account itself under the Tamil Nadu Online Gaming Authority regulations for real money games²⁷. At the national level, remote gaming platforms must run a full KYC and identification verification for each player prior to the first withdrawal or cash-out request, or within seven days from registration, whichever comes first²⁸. The result is that by the time money reaches your bank account, there is a verified chain: a KYC-checked account, a recorded deposit, a recorded withdrawal, and a tax deduction against your PAN.

Offline gambling has its own identity records. As noted earlier, Indian racecourse bookmakers record names and addresses for transactions of Rs 5,000 or more and winnings of Rs 10,000 or more⁶, and Japanese lottery prize claims require photo ID⁵. These records tie a specific person to a specific win, which is precisely what a source-of-funds question is asking.

If you are an expat or visitor

Visitors and expats face one extra layer: the win happens in one country and the tax question may follow you home. A few practical points from the region:

• Where you play determines what paper exists. A Japanese racing payout generates tickets and, if you file, a tax calculation based on the three-item note¹. A Vietnamese betting win only becomes taxable once it passes VND 20 million, and the tax falls on the amount by which it exceeds that limit²⁶. A Singapore Toto win needs no declaration in Singapore²³, but your home country may see things differently.
• Shared prizes need proof at the moment of claim, not later. Vietnam's rule that co-winners must present legal proof of the split, or the whole prize is taxed to one person⁴, bites hardest for groups of friends or colleagues who pool tickets across borders.
• Some winnings never become yours at all in edge cases. In Macau, under Law No. 10/2012, winnings of a person banned from gaming, after deducting losses, vest in the Macau SAR²⁹. A banned person's "win" produces no proof of source because it is not their money.
• Keep records in the currency you received them. Converting figures later invites disputes; the ticket, receipt or statement in its original currency is the primary evidence.

For the cross-border questions, see tax on winnings for tourists and non-residents, expats and tax residency, and home-country tax on winnings.