Missouri · Central Time
St. Louis, MO Area Codes
St. Louis is served by 2 area codes (314, 557). Here's which is original, which are overlays, and how to pick one for a new local number.
Last updated October 1, 2026
Area codes serving St. Louis
St. Louis sits in Missouri, part of the Midwest region and the Central Time zone. Its numbers are spread across an overlay of 2 codes that all cover the same ground: 314, 557.
The original code is 314 (in service since 1947). As the area ran low on numbers, regulators added overlay codes on top instead of splitting the city, so longtime residents kept their numbers while new lines received a newer code.
| Code | Area served | In service |
|---|---|---|
| 314 | St. Louis city and most of St. Louis County in eastern Missouri | January 1, 1947 |
| 557 | St. Louis city and most of St. Louis County in eastern Missouri | August 12, 2022 |
Nearby cities sharing these area codes
- Florissant
- University City
- Kirkwood
- Maryland Heights
- Webster Groves
- Hazelwood
- Ferguson
- Creve Coeur
- Clayton
- Oakville
- Mehlville
- Affton
How to pick an area code for a new number
When you activate a new line in St. Louis, the carrier assigns whichever code has numbers available — you usually can't choose. If a specific code matters to you (for example the prestige of 314), ask the carrier whether any blocks remain, or request a number transfer. All codes here dial identically and cost the same.
Dialing in St. Louis
Because St. Louis is an overlay area, 10-digit dialing is mandatory: always dial the area code plus the seven-digit number, even for a neighbor. See 10-digit dialing and overlay area codes for the background. For every code in Missouri, visit the Missouri area codes page.
Quick answers
St. Louis area code FAQ
What area codes does St. Louis use?
St. Louis, MO is served by 2 area codes: 314, 557.
Which is the original St. Louis area code?
314 is the original code for St. Louis, in service since 1947; the others were added later for more numbers.
Do I need to dial the area code in St. Louis?
Yes. With multiple overlapping codes, 10-digit dialing is required for every call in this area.