In general, many gamblers prefer to use casino win/loss statements because they are easily obtained from the casino. As an alternative, the IRS recommends that a gambler use a gambling diary or log to record their transactions by gambling session. Typically, such reports total the gambler’s activity by year, activity, and location.įrequently, the IRS refuses to accept a casino’s win/loss statement as evidence of a gambler’s losses. A casino win/loss statement is a report or letter from a casino that summarizes a person’s gambling activity.