As Treasury has implemented FATCA

The Treasury Department has acknowledged that more information sharing would be appropriate. The compl pipo u1 teed FATCA pacts include commitments "to pursue equivalent levels of reciprocal automatic exchange in the future," according to an October 2012 letter from Treasury Assistant Secretary for Tax Policy Mark Mazur to members of Congress.

The IRS this year started disclosing to some foreign governments information about bank interest payments earned by their citizens with U.S. bank accounts. This has raised privacy concerns, particularly for Mexican nationals. The Texas Bankers Association is considering a lawsuit against the government to stop accountholder information sharing with Mexico, said Eric Sandberg, the group's president.

At the heart of FATCA is a law requiring more disclosure by non-U.S. banks of information about Americans' accounts to the Internal Revenue Service, with the goal of exposing Americans' efforts to dodge U.S. taxes through secret offshore accounts.

As Treasury has implemented FATCA, some countries - possibly including France, Germany and China - were said to be driving a hard bargain. They have been saying that if their banks have to tell the IRS about Americans' secret accounts, then U.S. banks should have to reciprocate by disclosing more information about the U.S. accounts of French, German and Chinese nationals.

"We are concerned with Latin American countries like Mexico," said Fran Mordi, senior tax counsel at the American Bankers Association. "In the past, U.S. banks didn't report interest payments to non-resident aliens ... IRS is now saying you have to report that."

The Texas Bankers Association is considering a lawsuit against the government to stop accountholder information sharing with Mexico, said Eric Sandberg, the group's president.

Treasury officials have said Mexico's tax-collecting agency was carefully vetted and that officials checked with other U.S. agencies that share sensitive information with Mexico before agreeing to provide the tax information.

"The United States should be moving toward full reciprocity," said Georgetown Law School Professor Itai Grinberg, a end in China online shoppingformer Treasury official, adding it would be "deeply hypocritical" of the United States to ask for U.S. taxpayer information "without offering some kind of reciprocity."