The following answer comes courtesy of Jean Scott.
I certainly understand the need to protect personal information by not carrying Social Security cards that could be lost or stolen, then used to steal your identity. In addition, there are no federal or state laws that unless you show your Social Security card, you won't be paid a W-2G jackpot.
However, I have heard of cases in which players have had this problem when their W-2G jackpot amount was held up until they presented some proof of their SSN. One concerned a "foreign-looking" person who was acting "suspiciously."
But these cases are, in my experience, extremely rare. Almost all casinos routinely take your word when you give them your number. Some casinos might require you to sign a Form W-9; this certifies, under penalty of perjury, that the number you gave them is truly your SSN.
The main thing is that you can't refuse to give a casino your Social Security number. Well, technically, you can refuse, but you won't get paid! The government requires that the casinos put a Social Security number on all W2-G's forms that they issue.
So bottom line: Rather than risk carrying my Social Security card to a casino, I'd assume that the casino will take your number when you tell it to them. If not, volunteer to sign a W-9. Those two steps should work in 99.99% of jackpots.
Better known as "The Queen of Comps," Jean is author of several HP titles, including Tax Help for the Frugal Gambler, The Frugal Gambler, and More Frugal Gambling
