Don't expect this to be the standard result for any future snitches on corporate tax evaders, but the IRS did make good for at least one informant:
The Internal Revenue Service awarded tax whistleblower and former UBS AG banker Bradley Birkenfeld $104 million for providing the agency with insider information in UBS's illegal encouragement of secret offshore accounts by U.S. taxpayers. Mr. Birkenfeld's lawyers said it is believed to be the largest reward ever given to an individual whistleblower in the U.S. The Internal Revenue Service issued a statement confirming the award had recently been made, because Mr. Birkenfeld signed a disclosure waiver, but didn't comment on whether it is the largest whistleblower award.
He was recently released to a halfway house after serving part of a 40-month sentence for a felony conviction. In 2008, he was charged with withholding information about his own role in the plot, concerning his relationship with a wealthy California developer. He pleaded guilty to one count of conspiracy.