The 557 area code covers the same area as 314, including Saint Louis, Ladue and 5 more places in Missouri.
Area code 557 is in Missouri, on Central Time. In the 557 area, phone numbers are given out in the City of St. Louis. It has been in service since August 12, 2022. 314 covers the same area, so two neighbours can have different area codes.
- Where
- City of St. Louis, Missouri
- Time zone
- Central Time
- In service since
- August 12, 2022
- Shares its area with
- 314 (since 1947)
- Prefixes in use
- 83
- How to dial
- Local calls need all 10 digits: 557-555-0142.
Find out who called you from a 557 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (557) number is on today, use our free carrier lookup.
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Saint Louis holds 43% of the phone prefixes in area code 557.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 83 prefixes in use shows where 557 numbers are actually given out.
- Saint Louis36 prefixes, 43%
- Ladue17 prefixes, 20%
- Kirkwood12 prefixes, 14%
- Creve Coeur6 prefixes, 7%
- Mehlville5 prefixes, 6%
- Sappington5 prefixes, 6%
- Oakville2 prefixes, 2%
AT&T Mobility holds the most phone number prefixes in area code 557: 23 of 83.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 83 prefixes in use in 557 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| AT&T MobilityMobile network | 23 | 28% |
| Teleport (AT&T)AT&T's business phone network | 15 | 18% |
| Five9 | 2 | 2% |
| T-MobileMobile network | 2 | 2% |
| Terra Nova Telecom | 2 | 2% |
| 8x8Cloud phone platform for apps and businesses | 1 | 1% |
| 11 other carriers | 38 | 46% |
99% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
557 started in 2022 as an overlay on 314, and its ground has not changed since.
2022
557 starts on August 12, 2022, as an overlay on 314: new numbers on the same ground.
A 557 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 557 are 636, 573 and 618.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
These are the questions people ask most about area code 557.
Where is area code 557?
557 covers Saint Louis, Ladue, Kirkwood and Creve Coeur and 3 more places in Missouri. In the 557 area, phone numbers are given out in the City of St. Louis.
What state is area code 557 in?
Missouri. 557 is a Missouri area code on Central Time.
What cities use area code 557?
The places holding the most 557 prefixes are Saint Louis, Ladue, Kirkwood, Creve Coeur, Sappington, Mehlville and Oakville. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 557?
No single phone company owns 557. NANPA's records show AT&T Mobility holds the most 557 prefixes, 23 of 83, followed by Teleport (AT&T) and Five9. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 557 in?
557 is on Central Time.
When did area code 557 start?
557 went into service on August 12, 2022, as an overlay on 314: new numbers for the same area.
Is 557 the same area as 314?
Yes. 314 (since 1947) covers the same ground as 557. Nobody's number changed when it was added; new lines simply get whichever code has numbers left, so two neighbours can have different codes.
How do I dial a 557 number?
Local calls need all 10 digits: 557-555-0142.
Is 557 a toll-free number?
No. 557 is a regular area code for Saint Louis and Ladue in Missouri, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 557?
The closest are 636 (Saint Charles, Missouri), 573/235 (Columbia, Missouri), 618/730 (Collinsville, Illinois) and 217/447 (Springfield, Illinois), measured between the centres of each area.
Who called me from a 557 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 557 a scam?
557 is a real Missouri area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.