314 Area Code: St. Louis and the 557 Overlay

The essentials

314 area code: quick facts

How 314 became the St. Louis code

The history of 314 is a story of a code that kept shrinking toward St. Louis until a split no longer made sense. Each step below comes from an FCC table or a PSC order.

1. January 1947: Area code 314 opens, according to the FCC table of area code opening dates. The FCC lists other Missouri and Illinois codes, such as 816 and 312, with the same date.
2. January 1996: Area code 573 opens (FCC). A 1998 PSC order says the 573 code was split from a larger 314 area under the PSC's 1995 exhaustion case, and refers to the 314/573 split taking effect in January 1996.
3. November 25, 1997: The PSC opens case TO-98-212 to address the coming exhaustion of central office codes in the reduced 314 area. A September 1997 industry report had projected that 314 would run out in the fourth quarter of 1999.
4. July 22, 1998: The PSC orders a two-way geographic split proposed by the Office of the Public Counsel, rather than an overlay, which Southwestern Bell and several other parties had asked for.
5. January 6, 1999: The PSC is notified that the new code 636 has been assigned for the 314 split.
6. May 22, 1999: Permissive dialing for the 314/636 split begins at 12:01 a.m., under a PSC order of February 9, 1999. The FCC lists 636 as opened in May 1999. Mandatory dialing followed on February 26, 2000.
7. October 24, 2000: The PSC adopts an overlay plan for 314.
8. September 25, 2001: The PSC delays the overlay indefinitely to test whether number conservation would work. The PSC later said the overlay "remained on hold for over 20 years."
9. October 24, 2021: Ten-digit local dialing becomes mandatory in 314, so that 988 can work as the three-digit crisis line.
10. August 12, 2022: The earliest date that numbers with the 557 area code can be activated in the 314 region (PSC). The FCC lists 557 as opened in August 2022.

Where area code 314 is used

The PSC says the 314 area code serves communities "such as, but not limited to," St. Louis, Overland, Bridgeton, Florissant, Webster Groves, Creve Coeur, Kirkwood, and Sappington. That is the regulator's own list, and it is a sample, not a full one.

The boundary of today's 314 goes back to the 1998 split. The PSC adopted the Public Counsel's two-way split, which kept 314 for an area described in the order "roughly" as running from the meeting of the Missouri and Mississippi rivers, south along the Mississippi to the line between St. Louis County and Jefferson County, and back to the Missouri River along I-270 and US 40/61. The order says this boundary was the same one that separated the mandatory and optional parts of the St. Louis Metropolitan Calling Area. The remaining exchanges of the old 314 area received the new code, which became 636.

The maps attached to that order were not published in the PSC's bound reports, and the sources checked do not include an official list of every exchange in 314 today. Treat the boundary above as a description from 1998, and confirm a specific address with your phone provider.

Why 314 added a code

314 has run short of numbers three times. In 1995 the PSC relieved it with a split that created 573. In its 1998 order, the PSC noted that the evidence in the 1995 case suggested the 573 split would give 314 about eight years of relief. Instead, a September 1997 industry report projected that the reduced 314 would run out in the fourth quarter of 1999, and the 1999 order said 314 was operating under a jeopardy plan, rationing its remaining central office codes.

The 1998 order weighed a split against an overlay. The PSC found advantages and disadvantages in both, and chose the split for its customer impact. It also found that 1,000s-block number pooling, sequential number assignment, and rate center consolidation could "dramatically prolong" the life of the area codes, and opened case TO-99-14 to plan them for the St. Louis area.

The arguments in that order still explain how overlays work. Supporters of an overlay, including GTE, the PSC Staff, and Southwestern Bell, said every existing customer would keep their ten-digit number and no boundary would change, so businesses would avoid reprinting stationery, checks, and signs. They also said a new code would last longer because its prefixes could be assigned anywhere in the old 314 footprint. Opponents said different area codes in the same home, business, or neighborhood would cause confusion, that alarm and elevator phones programmed with seven digits would need changes, and that overlays had only been tried in a few areas nationwide. The Public Counsel also argued that business customers would prefer old 314 numbers, because a new code would suggest they were new to the area.

Those conservation steps are why the overlay waited. The PSC adopted an overlay plan for 314 in October 2000, then delayed it in September 2001 to test number conservation. Chairman Ryan Silvey later said, "Telephone number conservation efforts were successful and as a result, implementation of an overlay relief plan for the 314 area code remained on hold for over 20 years." The overlay came back when NANPA told the PSC that 314 was again nearing exhaustion, projecting the third quarter of 2022. The PSC handled the overlay in case TO-2022-0010.

NANPA's April 2026 analysis projects that the combined 314/557 area will run out of numbers in the fourth quarter of 2060, based on data as of March 1, 2026. The same table shows the estimate moving by 12 quarters since the previous analysis, so treat the date as an estimate.

Area codes related to 314

The table shows how each Missouri code relates to 314, based on the PSC and FCC sources in this guide. Other codes serve areas outside the sources checked, so the table does not claim to show every neighbor.

The PSC's 557 fact sheet includes a map of Missouri's area codes, showing 314 alongside 636, 573, 660, 816, and 417. The sources checked do not describe exactly where the Illinois codes across the Mississippi meet 314, so they are not listed.

The 557 overlay that shares 314's territory

An overlay adds a new area code to the same geographic area, so existing numbers do not change. The PSC says all existing 314 customers kept their area code and telephone numbers, and that the 557 code "will co-exist everywhere in this region with the 314 area code."

• 557 (numbers from August 12, 2022): the only overlay on 314 so far.

The PSC lists these key facts about the overlay:

• Telephone numbers, including the current area code, do not change.
• The price of a call, the coverage area, and other rates and services do not change due to the overlay.
• What is a local call now remains a local call.
• Customers in the overlay region must dial 10 digits for local calls.

Because the codes overlap, two neighbors on the same street can have different area codes, one 314 and one 557. That is the confusion overlay opponents warned about in 1998, and it is why the PSC asked customers to include the area code on their websites, personal and business stationery, printed checks, advertising materials, contact information, and even personal or pet ID tags. A number printed with only seven digits no longer tells a caller which of the two codes to dial.

Time zone and daylight saving time

Area code 314 uses Central Time. The tz database zone table lists America/Chicago as "Central (most areas)." It does not name Missouri, so we also checked federal rules. Under 49 CFR 71.6, the central zone is the part of the United States west of the eastern and central boundary in 49 CFR 71.5 and east of the central and mountain boundary in 49 CFR 71.7. The eastern boundary has segments headed Indiana-Illinois, Kentucky, and Tennessee, and the mountain boundary has segments for South Dakota, Nebraska, Kansas-Colorado, and the southern plains. On our own reading of those rules, St. Louis lies between the two lines. None of these sources names St. Louis itself.

NIST says daylight saving time begins at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November. The NIST page lists Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and Arizona as places that do not observe it, and Missouri is not on that list. In 2026, NIST gives March 8 and November 1 as the change dates.

How to dial a 314 number

North American numbers have three parts: a country code, a three-digit area code, and a seven-digit local number. NANPA says the ITU assigned country code 1 to the NANP area. The PSC asks customers to identify their number as a 10-digit number (3-digit area code plus 7-digit number) and to include the area code when giving it to others.

Ten-digit dialing in 314 came before the overlay. On July 16, 2020, the FCC designated 988 as the three-digit code for the suicide prevention lifeline. Because 988 was a working prefix in 314, the PSC's FAQ says every customer in the entire 314 area code would move to 10-digit local dialing. Customers could start dialing 10 digits from April 24, 2021, and it became mandatory on October 24, 2021. After that date, a local call dialed with seven digits may not go through, and a recording asks you to hang up and dial again with the area code. The same change covered 417, 660, and 816. A later PSC release ties the requirement to July 15, 2022; the FAQ dates are the ones used here.

• Local calls within 314 and 557: dial the area code plus the seven-digit number.
• Long distance: dial 1 plus the area code plus the number.
• Three-digit codes such as 911, 711, and 988, and any 211, 311, 411, 511, 611, or 811 service in your community, still work.
• From a multi-line system, such as a hotel or office, you may still need to dial a prefix such as 9 first, the PSC FAQ says.

The PSC also asks customers to check anything that stores a number, such as contact lists, PBXs, fax machines, speed dialers, call forwarding settings, voicemail services, medical alert devices, and security systems and gates, and to make sure the equipment accepts 557 as a valid area code.

Caller ID and scams with a 314 number

The FTC warns that "Scammers can make any name or number show up on your caller ID." That is called spoofing. Scammers can also match the first six digits of your own number, which the FTC calls neighbor spoofing.

• If you pick up and do not recognize the caller, the FTC advises that you hang up.
• Letting an unknown call go to voicemail is one option.
• The FTC says call blocking is your best defense against unwanted calls.

The sources checked do not say that 314 numbers are targeted more than others. A 314 number shows the code that was assigned, not who is calling or where they are. Because 557 shares the same region, a 314 caller ID is not the only sign of a St. Louis caller, and a spoofed 314 number is no sign at all.

Choosing a 314 number for a business

314 is the long-standing St. Louis code, but since August 2022 the 557 code co-exists everywhere in the region. A new line may carry 557 instead of 314, and the area code does not show which part of the region the business is in.

Because the two codes share territory, route calls by team or extension, not by area code. Ask your provider which code a new line gets, since that depends on its current inventory.

Whether a specific 314 number can be assigned to your business depends on your phone provider and its current inventory. This guide does not make claims about availability.

Important: Confirm availability with your provider before you plan a campaign or print a number on materials.

Before you use a 314 number

• Confirm the number is available from your provider, and get its terms in writing.
• Ask who owns the number and whether it can be moved to another provider if you switch.
• Confirm which area code your line uses. 314 and 557 serve the same region.
• Set 10-digit dialing for numbers in both codes before you go live, because local calls in 314 require 10 digits.
• Make sure your phone system, alarms, and other equipment accept 557 as a valid area code, as the PSC advises.
• Print the full 10-digit number with the area code on your website, stationery, and advertising.
• Route calls by team or extension, because 314 and 557 share one territory.
• Plan for caller ID. A 314 number does not prove who is calling, and neighbor spoofing copies the first six digits of your own number.

Related guides and tools

• 312 area code guide: Chicago, another Midwest city on Central Time, for comparison with St. Louis.
• 612 area code guide: Minneapolis, another original 1947 Midwest code, for comparison with St. Louis.
• 615 area code guide: Nashville, another Central Time metro, for comparison with St. Louis.
• What is a DID number?: what a DID is, local versus toll-free types and porting rules.
• Business phone number porting: how number porting works, how long it takes and how to prepare.
• Full list of U.S. area codes by state, with the overlay codes and time zone for every code.
• Browse all U.S. area code guides, including overlay codes that do not have their own guide yet.
• Business phone system and call routing for local numbers in St. Louis.

Frequently asked questions