“[Reciprocity] is a great concept if authorities on both sides are reputable, adhere to standards of confidentiality and have a government structure that controls this information,” said Carlos Fernandez-Guzman, president of Miami-based Pacific National Bank, where more than 70 percent of depositors are foreigners. “But that is not necessarily the case in all these countries.

“I have Latin American customers who say ‘don’t send me any bank statements; keep them in the U.S. and I’ll pick them up when I come.’ All of that is for security reasons,” he said. “They don’t want people knowing the extent of their wealth, especially what’s in the U.S., because in their home country it’s a volatile political and criminal environment.”

At the very least, the new rules are causing jitters. His larger depositors, “especially the top 5 to 10 percent,” Fernandez-Guzman said, are “actively beginning to do due diligence.’’

One option for international clients is to put their money into noninterest-bearing accounts that are not subject to the disclosure requirements. Savings accounts are earning little interest at current low rates, and the full amount in checking accounts is insured under the FDIC’s Transaction Account Guarantee program. Though that is set to expire at the end of the year, observers say it could be extended.

The potential loss of foreign deposits comes at the same time that banks face higher capital reserve requirements and a slew of new regulations requiring extensive — and expensive — compliance efforts.

“All of this kind of adds up to the whole regulatory puzzle that we’re all trying to navigate,” said Raul Valdes-Fauli, president and CEO of Professional Bank in Miami. “There’s a lot of uncertainty, and it’s hard to make sure you’re getting your arms around it and implementing the necessary measures. This is a huge burden, especially on smaller banks.”

Still, Miami’s advantages of language and geography— factors that originally helped develop the city’s banking and business culture — will most likely continue to attract foreign depositors, especially from Latin America.

“Miami will continue to be Miami,” said Thomas, the banking expert. “Just at a greater cost.”