Area Code 309
Illinois
Area code 309 serves Illinois, primarily Peoria, in the Central Time (CT) time zone. It has served the region since 01-Jan-1957.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 861 (Peoria).
In service since: 01-Jan-1957
Demographics & Economics
- Total Population
- 1,156,724
- Population Density
- 72 people/sq mibelow U.S. average (U.S.: 93 people/sq mi)
- Median Household Income
- $66,768below U.S. median (U.S.: $75,144)
- Poverty Rate
- 12.6%near U.S. average (U.S.: 11.5%)
- Unemployment Rate
- 4.8%above U.S. average (U.S.: 3.6%)
- Education Attainment
- Bachelor's Degree+29.5%below U.S. average (U.S.: 33.7%)High School or Lower33.2%
Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.
See how this area code compares to all US area codes in the Statistics dashboard.
Time Zone
- Central Time (CT)
NANPA Relief Status
According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.
Source: NANPA NPA Relief Planning Reports · See all relief planning statuses
Current Time
Prefix Utilization
Geographic Coverage
State
IL
Major Cities
- Peoria
- Bloomington
- Normal
- Moline
- Rock Island
- Pekin
- Galesburg
- East Peoria
- East Moline
- Morton
- Washington
- Macomb
- Canton
- Kewanee
- Monmouth
- Silvis
- Geneseo
- Chillicothe
- Bartonville
- Peoria Heights
- Colona
- Eureka
- Milan
- Creve Coeur
and 196 more cities
Historical Timeline of Area Code 309
Area code 309 was created on January 1, 1957, as a split from area code 815 that merged the western portion of 815 with the northern portion of area code 217, forming a new numbering plan area for west-central Illinois. It remained the only new area code in Illinois for over three decades until area code 708 was created in 1957. Source: Wikipedia
- 1947: Illinois divided into four original NPAs: 217 (central), 312 (Chicago), 618 (southern), and 815 (northern). All part of the 86 original North American area codes. Source: Wikipedia
- January 1, 1957: Area code 309 created from a split of area code 815. The western portion of 815, including the Illinois side of the Quad Cities, was combined with the northern portion of area code 217 to form the new NPA. Source: Wikipedia
- October 19, 2000: The Citizens Utility Board and Illinois Attorney General petitioned the ICC under Docket 00-0681 for number conservation and pooling measures in area codes 309, 217, 618, and 815 to forestall the need for new area codes. No relief was required for 309 at that time. Source: ICC Docket 00-0681
- July 16, 2020: The FCC designated 988 as the nationwide Suicide Prevention Lifeline code under Order FCC 20-98. Area codes with 988 as a working prefix were required to convert to 10-digit dialing. Source: NANPA PL-577
- October 24, 2021: Area code 309 transitioned to mandatory 10-digit dialing due to the 988 conflict, making it one of the first area codes forced to adopt 10-digit dialing before an overlay was even announced. Source: Wikipedia
- July 7, 2021: Industry reached consensus on an all-services overlay adding area code 861 to the 309 NPA. The Illinois Commerce Commission took no action within the 90-day window expiring November 11, 2021. Source: ICC Press Release
- January 10, 2022: NANPA Planning Letter PL-577 formalized the all-services distributed overlay adding 861 to the 309 NPA, covering 20 counties in west-central Illinois. Source: NANPA PL-577
- February 24, 2023: Area code 861 officially went into service. New customers in the 309 region may receive 861 numbers. The two codes now coexist as an all-services overlay. Source: ICC Press Release
Regulatory History
Area code 309 has been shaped by three significant regulatory events spanning over two decades, from early number conservation efforts to the FCC 988 mandate that fundamentally altered its relief trajectory. Source: NANPA PL-577
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 2000 | Number conservation petition | ICC 00-0681 | The Citizens Utility Board and Illinois Attorney General petitioned the ICC for number conservation and pooling in area codes 309, 217, 618, and 815. The petition demonstrated early concern about numbering resource management in Illinois and forestalled the need for new area codes at that time. Source: ICC Press Release |
| 2020 | FCC 988 Suicide Prevention Lifeline designation | FCC 20-98 | The FCC designated 988 as the nationwide Suicide Prevention Lifeline code, eliminating the geographic split relief option for area codes with 988 as a working prefix. This forced area code 309 to adopt an overlay with 861 instead of a geographic split, and required mandatory 10-digit dialing. Source: NANPA PL-577 |
| 2022 | All-services overlay implementation | NANPA PL-577 | NANPA implemented an all-services distributed overlay adding area code 861 to the 309 NPA. Industry consensus was reached July 7, 2021; the ICC took no action within the 90-day window. 861 central office codes became available December 20, 2022, and went in-service February 24, 2023. The overlay covers 20 counties in west-central Illinois. Source: NANPA PL-577 |
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 309).
| County | Population | Share |
|---|---|---|
| Peoria, IL | 185,129 | 16.0% |
| McLean, IL | 178,063 | 15.4% |
| Rock Island, IL | 151,635 | 13.1% |
| Tazewell, IL | 147,084 | 12.7% |
| Woodford, IL | 65,013 | 5.6% |
| Knox, IL | 60,366 | 5.2% |
| Henry, IL | 58,455 | 5.1% |
| Warren, IL | 52,892 | 4.6% |
| Fulton, IL | 42,014 | 3.6% |
| Mercer, IL | 32,500 | 2.8% |
| McDonough, IL | 29,690 | 2.6% |
| Stark, IL | 26,843 | 2.3% |
| Marshall, IL | 26,643 | 2.3% |
| Whiteside, IL | 21,625 | 1.9% |
| Henderson, IL | 19,408 | 1.7% |
| Bureau, IL | 19,348 | 1.7% |
| De Witt, IL | 12,645 | 1.1% |
| Mason, IL | 11,828 | 1.0% |
| Hancock, IL | 4,842 | 0.4% |
| Schuyler, IL | 3,148 | 0.3% |
| Piatt, IL | 2,577 | 0.2% |
| Logan, IL | 2,444 | 0.2% |
| Livingston, IL | 2,051 | 0.2% |
| Ford, IL | 481 | 0.0% |
Area Code 309 Family Tree
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Area code 309 was originally assigned in 01-Jan-1957 to serve IL. Over the years, it has generated 1 descendant area code through a combination of geographic splits and overlays as demand for telephone numbers grew.
Call Context
This area code spans a mix of urban centers and rural communities across IL, with Peoria as a primary city.
Nearby Area Codes
Area codes geographically closest to 309.
Other Area Codes in Illinois
Area codes that also serve Illinois, linked for easy comparison.