Battling tax evasion, IRS finds 'substantial' data on offshore accounts

The IRS told The Hill that it had acquired the data months ago, and that the information was already helping the agency to start or speed up tax evasion cases – with many more cases expected to follow.

But the agency would not comment on how it obtained the data, but did say that the three countries acquired it independently of one another. The data also appears similar to information that the International Consortium of Investigative Journalists (ICIJ) reported on last month, as part of a 15-month investigation that found 2.5 million secret files.

Bill Buzenberg, the executive director of the Center for Public Integrity, ICIJ’s parenty company, told The Hill that the IRS would be able to make lots of headway with the information, by comparing the data to tax records.

As the IRS noted in its release, taxpayers are not barred from holding assets offshore, but often do so to escape their tax bill. Buzenberg added that the IRS told his group that taxpayers holding assets in tax havens are more likely to come forward after high-profile stories dealing with tax evasion.

“This really could be about the biggest tax investigation we’ve ever seen,” Buzenberg said of the IRS’s announcement.

On Thursday, the IRS urged taxpayers to take advantage of a voluntary offshore disclosure program if need be, after reviewing their offshore holdings. Thousands of taxpayers have already taken part in that program.

The federal government has been increasing its efforts against offshore tax evasion for much of President Obama’s time in office.

As part of that work, the IRS is also continuing to implement the Foreign Account Tax Compliance Act, or FATCA, and has signed information sharing agreements with Switzerland and other countries.

UBS, the Swiss banking giant, helped start the increased information sharing by handing over data on some 4,450 clients after having been charged by U.S. authorities with helping American clients avoid taxes.

Switzerland recently signed an agreement with the U.S. to implement the Foreign Account Tax Compliance Act, a law Congress passed in 2010 to battle tax evasion.

UBS, the Swiss banking giant, had been charged by federal authorities with helping U.S. clients evade taxes, and later turned over information on some 4,450 clients.