This is a theoretical question. How does the IRS in the USA treat the winnings of a gambler. The example to be considered is a gambler who wins betting on horse races, sports, and in Casinos in the USA. Does the IRS treat the "amatuer", occasional gambler differently to a person they would regard as a " professional gambler" ?
What if the gambler is a US citizen, and, much more importantly, what if they are a "foreign national" visiting the USA, for example on a six or twelve month "tourist visa"..so no green card etc. ?

Thanks Gen Lee. I'm assuming that applies to US citizens. It's the example of the tourist that most interests me.

If you make money, they'll tax it.

Casinos will issue you a 1099 for the winnings, which will require you have a SSN or ITIN. Otherwise they will withhold tax on the monies before you even receive it. This way they can match up your income to the expected tax return they will receive. And if you don't intend to file they have the withholding tax already at what is likely a much higher rate than you would have to pay.

Umm, what is a 1099? And what is a SSN & ITN ? Best to assume I know nothing about the US tax system.

This is not for "real use", so there is no responsibility on the part of those offering this advice. As with all financial advice, readers cannot assume that any advice offered in this thread is necessarily correct, and they should consult the properly qualified experts rather than rely on anything posted here.

This link seems quite instructive:

https://www.artiopartners.com/nonresident/gambling-winnings-tax-foreign-nationals/

Am I correct in assuming a licensed bookmaker in the USA would act similarly to a Casino in the USA ? Issuing this 1099 thingy ? And requiring a SSN or ITIN ?

@ Bo Sox..loved that simple post..I think that's the default position of most taxation authorities just about everywhere.

I heard there was a member here that can get you a SSN card and even some oil paintings.

Yes if they are legit MM they will have the same requirements.

LoL, or an oil painted SSN.

1099 is a record of the income and taxes withheld at federal, state, and local levels.

SSN (social security number) and TIN (taxpayer identification number) are identity numbers for tax records used when filling out tax forms to make them different for payers, businesses, or trusts.

Great stuff, thanks. That's a big help for me.