Treasury finalizes the Customer Identification Program rule under PATRIOT Act Section 326

The Treasury Department and federal banking regulators published the final Customer Identification Program (CIP) rule on May 9, 2003, operationalizing Section 326 of the PATRIOT Act with compliance required by October 1, 2003. The rule required banks to collect name, date of birth, address, and a government-issued identification number for every new account holder — but explicitly allowed non-U.S. persons to use a taxpayer identification number, such as an ITIN, in lieu of a Social Security number. This clarification gave ITIN holders formal legal standing to open bank accounts, creating a documented pathway for undocumented immigrants to enter the mainstream financial system.