The U.S. is negotiating with Japan and Switzerland on detailed procedures for sharing U.S. account holders' offshore bank information under an anti-tax-evasion law scheduled to take effect in 2013, the Treasury Department announced.

Banks and financial institutions from around the world have been complaining to the U.S. about the burdens caused by the Foreign Account Tax Compliance Act, or Fatca. The agreements announced today are part of the governments' efforts to create a smoother process for information exchange.

Under the law, overseas banks will be required to inform the Internal Revenue Service annually about the balances and activity in their U.S. customers' accounts. The U.S. can impose a 30 percent tax on some U.S.-related payments being sent to financial institutions outside the country that don't comply with the rules.