<P> The National Do Not Call Registry is a database maintained by the United States federal government, listing the telephone numbers of individuals and families who have requested that telemarketers not contact them . Certain callers are required by federal law to respect this request . Separate laws and regulations apply to robocalls in the United States . </P> <P> On June 27, 2003, the U.S. Federal Trade Commission (FTC) opened the National Do Not Call Registry in order to comply with the Do - Not - Call Implementation Act of 2003 (Pub. L. 108--10, was H.R. 395, and codified at 15 U.S.C. § 6101 et . seq .), sponsored by Representatives Billy Tauzin and John Dingell and signed into law by President George W. Bush on March 11, 2003 . The law established the FTC's National Do Not Call Registry in order to facilitate compliance with the Telephone Consumer Protection Act of 1991 . </P> <P> Registration for the Do - Not - Call list began on June 27, 2003, and enforcement started on October 1, 2003 . Since January 1, 2005, telemarketers covered by the registry have up to 31 days (initially the period was 90 days) from the date a number is registered to cease calling that number . Originally, phone numbers remained on the registry for a period of five years, but are now permanent because of the Do - Not - Call Improvement Act of 2007, effective February 2008 . </P>

Who has authority to implement do not call rules