The US Securities and Exchange Commission voted unanimously to formally propose requiring firms to use interactive data for their financial filings.

The proposed rule would require all U.S. companies to provide financial information using interactive data beginning next year for the largest companies, and within three years for all public companies. The SEC says that this new technology will get financial information to investors faster, more reliably, and at a lower cost.

“This is all about bringing investors better, faster, more meaningful information about the companies they own,” said SEC chairman Christopher Cox. “It would transform financial disclosure from a 1930s form-based system to a truly 21st century model that taps the power of technology for the benefit of investors.”

Since 2005, companies have voluntarily submitted to the SEC financial information in interactive data format. The rules proposed today would require companies to provide this information according to a phase-in schedule.

The SEC’s proposed schedule would require companies using U.S. GAAP with a public float over $5 billion (approximately the 500 largest companies) to make financial disclosures using interactive data formatted in eXtensible Business Reporting Language (XBRL) for fiscal periods ending in late 2008. If adopted, the first interactive data provided under the new rules would be made public in early 2009.

The remaining companies using U.S. GAAP would provide this disclosure over the following two years. Companies using International Financial Reporting Standards would provide this disclosure for fiscal periods ending in late 2010. The disclosure would be provided as additional exhibits to annual and quarterly reports and registration statements. Companies also would be required to post this information on their websites.

The required tagged disclosures would include companies’ primary financial statements, notes, and financial statement schedules. Initially, companies would tag notes and schedules as blocks of text, and a year later, they would provide tags for the details within the notes and schedules.