Area code 557 – Missouri
557 has served Missouri since 2022, split from 314. It is still largely empty: 84 of 786 number blocks allocated. AT&T is the largest holder with 45.2% of blocks, ahead of Onvoy / Inteliquent at 22.6%. It shares its geography with overlay codes 314, so local calls take all ten digits. Spam complaints are comparatively rare: 24 in the 33 days to 30 October 2026, 397th of the 422 codes with five or more complaints.
Who holds 557 number blocks
Share of the 84 assigned NXX blocks (10.7% of the 786 possible), across 18 carriers. This is share of number blocks, not of subscribers.
- AT&T45.2%
- Onvoy22.6%
- Other CLEC / VoIP11.9%
- Verizon9.5%
- Charter3.6%
- T-Mobile2.4%
- Comcast1.2%
- Dish1.2%
- TPx1.2%
- 8x81.2%
Spam complaints naming 557
FTC Do Not Call complaints where the caller ID was a 557 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 557
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 7.
Timeline
- 2022 557 goes into service, split from or overlaid on 314.
More about 557
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 557
What state is area code 557?
Missouri. It covers the same area as 314/557.
Is a call from 557 a scam?
Not by itself. 557 drew 24 FTC complaints in the 33 days to 30 October 2026, 397th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 557 numbers?
AT&T holds the largest share of assigned number blocks at 45.2%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 557?
Yes – ten digits for local calls in 557, because it shares its area with another code.
Sources and verification
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.