North American Numbers Source-cited · ownership disclosed
Area code
557
In service
United States · since 2022

St. Louis (overlay)

An all-services overlay added in 2022 covering the same St. Louis geography as area code 314.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
St. Louis (overlay)
Type
geographic
Status
in service
In service since
2022
Projected exhaust
2060 Q4

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 557 is

City of St. Louis and inner St. Louis County suburbs (same footprint as 314)..

Communities served wholly or partly by 557:

St. LouisKirkwoodWebster GrovesFergusonFlorissant

Shares the entire 314 service area as an overlay.

B · Relationships

How it relates to other codes

The codes 557 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Overlay · 2022 314 St. Louis 557 overlays the existing 314 numbering plan area.
Related · 1999 636 St. Charles / western St. Louis suburbs Adjacent western/outer St. Louis suburbs.
What's changing. Overlay of 314; both codes serve the same geography.
C · History

How 557 got here

2022-08-12
Placed in service as an overlay on the 314 area as available 314 numbers neared exhaustion.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
95
Prefixes available
705
Thousands-blocks assigned
759

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 557 with another code →
Sources
Wikipedia ↗
Area codes 314 and 557
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.