When my wife hit a jackpot on a slot machine at the Golden Nugget a couple of years back while waiting in the queue for the buffet ($1600 = very nice, but not enough to retire on!!) she did not have tax withheld but had to produce a passport as proof of UK citizenship. I was under the impression that there was a treaty that allows UK citizens at least (I can't answer for anyone else) not to pay tax on gaming wins, and believe that the same applies to US citizens who win over here (although gaming wins are not taxable in the UK - casino, lottery or betting shops). Of course, as James noted, it can always change!

James - I would be interested in a copy of your book if it is siomething available for individuals, just in case I do hit that big win next time I'm in Vegas!

Jason