Area Code Atlas

Overlay of area code 557 on 314

Area code 557 was overlaid on the 314 region in August 2022 to provide additional numbering capacity as existing numbers neared exhaustion.

Overlay relief plan for 314 approved, assigning 557 as overlay

On October 24, 2000, the Missouri Public Service Commission approved a relief plan for the 314 area code, assigning 557 as an all-services overlay for the same geographic area. The overlay was intended to address projected number exhaustion.

NPA 557 overlay on 314 announced

New NPA 557 to Overlay NPA 314 (Missouri)

NPA 557 Overlay of NPA 314 Implementation Date and Dialing Plan Change (Missouri)

Implementation of 557 overlay for 314 postponed indefinitely

On September 25, 2001, the Missouri Public Service Commission announced the indefinite suspension of the implementation of the 557 overlay for the 314 area code, citing conservation measures and a lack of immediate need for additional numbering resources.

NPA 557 overlay on 314 announced

NPA 557 to Overlay NPA 314 (Missouri)

NPA 557 overlay activated for 314

On August 12, 2022, area code 557 was activated as an all-services overlay for the 314 area code region, providing additional numbering resources for St. Louis and its inner suburbs as 314 neared exhaustion. Both area codes now serve the same geographic area, and ten-digit dialing is required.