Area code 557

About area code 557

Area code 557 is a geographic area code in Missouri, in service since August 12, 2022, according to the North American Numbering Plan Administrator (NANPA). It is an overlay: 557 and 314 cover the same territory, so neighbors on the same street can have different area codes. It is in the Central time zone. The places with the most assigned exchanges include St. Louis, Ladue, Kirkwood, and Creve Coeur. By population, its largest named places are St. Louis, Kirkwood, Creve Coeur, and Ladue.

Cities and towns in area code 557

557 holds 2.0% of the 4,168 central office codes assigned in Missouri, the 7th most of the state's 9 codes. 4 Census places could be matched to rate centers with 557 exchanges; the most populous are St. Louis (280,000), Kirkwood (29,348), Creve Coeur (18,533), and Ladue (8,937). Each place page lists the exact prefixes and carriers for that town.

How calls are dialed in 557

According to NANPA's dialing-plan data, local calls within 557 are dialed as ten digits (area code plus number) and toll calls as 1 plus ten digits. Because local calls need the area code, business cards, signage and website copy should always show the full ten-digit number. NANPA's dialing-plan note for this code reads: "1+10 digit permissible at service provider discretion"

Carriers with 557 numbers

18 carriers hold the 83 central office codes assigned in 557. New Cingular Wireless PCS, LLC - Il has the most, with 23 (28%). 82 of the codes (99%) are pooled, meaning the code holder shares blocks of 1,000 numbers with other carriers instead of using all 10,000 itself. The code holder is not necessarily the carrier serving a given number today, since numbers can be ported between providers.

Local calling areas in 557

NANPA assigns each central office code to a rate center, the local calling area that decides whether a call is local or toll. 557 has codes in 7 rate centers. Rate center names in the file are abbreviations; where one matches a Census place, the table links to that city's local-number page.

Number supply in 557

An area code has 800 possible central office codes that start with 2 through 9, a few of which are reserved (such as N11 service codes and 555). 83 are assigned in 557, 10% of 800. 83 were assigned in 2020 or later.

Getting a 557 number for your business

For $99 a month, Callata puts a team of up to 5 on one plan ($20 for each person after that): up to 3 local numbers, unlimited inbound calls, a pooled allowance of 1,500 outbound US and Canada minutes per user, browser and cell calling, voicemail transcription with urgency triage, recorded calls with AI summaries and business-hours routing, with E911 on every number.

Porting a number you already use in area code 557 is free, and business texting is available once the carrier registration (10DLC) is approved; the registration carries a one-time $49 fee. Which specific numbers are open in a given area code depends on carrier inventory at the time you sign up.

AI agents are optional: an AI receptionist or scheduler can pick up when the team is busy or closed, take a message, send a text or email, or transfer the call. They draw on prepaid AI minutes ($0.25/minute), disclose that they are AI, and outbound AI calls require prior consent and are limited to 8am–9pm.