Area code 314

Area code 314 was one of the original area codes created in October 1947. It originally covered most of the eastern half of Missouri, from the Illinois border to Jefferson City. It stretched along nearly the entire width of the state along the Mississippi River. It was split on January 7, 1996, when most of the western and southern portion was assigned to area code 573, leaving 314 to cover most of the Missouri side of the St. Louis metropolitan area.

The creation of 573 was intended to be a long-term solution. Within only two years, however, 314 was close to exhaustion once again due to the proliferation of cell phones, fax machines and pagers in the St. Louis core. The supply of numbers was further limited because the St. Louis LATA extends across much of the southern portion of Illinois, meaning several numbers in Illinois' 618 weren't available for use. As a result, 314 was reduced to its current size on May 22, 1999, when area code 636 was assigned to St. Louis' outer western suburbs. Before the introduction of number portability, 314 was used for all cell phones on the Missouri side of the St. Louis area.

In 2000, the Missouri Public Service Commission announced plans to add area code 557 as an overlay to area code 314, but postponed the implementation date (May 5, 2002) indefinitely, when the commission determined no immediate need for more phone numbers. Conservation measures such as number pooling staved off the immediate need for an overlay.[1] As of 2019, 314 is one of the few urbanized area codes that has not been overlaid, making St. Louis one of the largest cities where seven-digit dialing is still possible.

• List of NANP area codes
• North American Numbering Plan

• NANPA area code map of Missouri
• List of exchanges from AreaCodeDownload.com, 314 Area Code