The 557 area code serves St. Louis, Missouri, and nearby areas such as Florissant, Chesterfield, Kirkwood, Webster Groves, Clayton, and University City. It uses the Central Time Zone. Officials activated 557 on August 12, 2022, as an overlay for the existing 314 area code.
What Is the 557 Area Code?
The area code 557 is a telephone area code assigned to eastern Missouri, centered on St. Louis. The North American Numbering Plan Administrator (NANPA) introduced it to add capacity to a region where the original area code was running out of available phone numbers.
Where Is the 557 Area Code Located?
Area code 557 covers St. Louis City and St. Louis County, Missouri, along with a cluster of well-known inner-ring suburbs. Together, the 314/557 overlay region serves roughly 1.3 million people, making it one of the more densely populated numbering areas in the Midwest.
Cities and Counties Covered by 557
The 557 area code location footprint includes St. Louis and numerous surrounding communities. Commonly cited cities within its coverage area include:
History: When Was 557 Created?
Area code 557 location went into service on August 12, 2022. Officials made it the 437th area code activated in North America and the 7th assigned to Missouri. Officials created 557 to ease number shortages in the 314 area code as St. Louis’s population and business sector grew.
Is a 557 Area Code Number Safe? Scam Check
Yes, the area code missouri itself is legitimate. NANPA assigned it to cover real residents, businesses, and institutions in the St. Louis area, just as it does for any other standard geographic area code.

Time Zone and Current Local Time
The 557 area code sits entirely within the Central Time Zone (America/Chicago).
This keeps St. Louis businesses aligned with other major Midwest commercial hubs, including Chicago, Dallas, and Kansas City, making it easier to schedule calls, meetings, and customer support hours.
557 vs. 314: Understanding the Overlay
| Feature | Area Code 314 | Area Code 557 |
|---|---|---|
| Region served | St. Louis metro | St. Louis metro (identical) |
| In service since | Original St. Louis code | August 12, 2022 |
| Type | Geographic code | Overlay code |
| Time zone | Central | Central |
| 10-digit dialing required | Yes | Yes |
Because 314 and 557 share the same geographic footprint, all local calls in the region require 10-digit dialing (area code + phone number), even between two neighbors on the same street. This is standard practice in every U.S. overlay region and is not unique to St. Louis.
How to Get a 557 Area Code Number for Your Business
Businesses outside Missouri sometimes request a 557 number specifically to build a local presence in the St. Louis market, a major Midwest hub for logistics, agritech, healthcare, and technology.
Frequently Asked Questions (FAQs)
Conclusion
The 557 area code is a modern, legitimate numbering resource for the St. Louis, Missouri, metro area, created in 2022 to keep pace with the region’s growing demand for phone numbers. As an overlay to the long-standing 314 code, it shares the same territory, the same Central Time Zone, and the same trusted local identity, without displacing a single existing number.
