Area code
309
309 is a United States area code. Under the North American Numbering Plan it belongs to Illinois, which has 17 area codes in total.
Validate a number in 309
Paste a full number and the tool checks it against the numbering plan. It returns the standard formats, the line type the plan assigns and the area code region.
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Area code 309 at a glance
NANPA lists 780 central office codes (prefixes) in use in area code 309, held by 69 holders across 171 rate centers.
| Fact | Value |
|---|---|
| In service since | 1957-01-01 |
| Time zone | Central (C) |
| Assigned overlays | 861 (2023-02-24) |
| Prefixes in use | 780 |
| Pooled prefixes | 569 (73%) |
| Rate centers | 171 |
| Companies holding prefixes | 69 |
| Assignment dates on file | 2001-01-12 to 2026-06-24 (333 prefixes) |
| ZIP codes in its places | 179 |
Rate centers in area code 309
| Rate center | Prefixes | Share |
|---|---|---|
| PEORIA | 155 | 20% |
| BLOOMINGTN | 76 | 10% |
| ROCKISLAND | 41 | 5% |
| MACOMB | 23 | 3% |
| GALESBURG | 20 | 3% |
| MOLINE | 17 | 2% |
| PEKIN | 17 | 2% |
| EASTMOLINE | 16 | 2% |
| 163 other rate centers | 415 | 53% |
Who holds the prefixes in 309
Frontier North holds the most prefixes, 99 (13%). 73% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| Frontier North | 99 | 13% |
| Illinois Bell Tel | 83 | 11% |
| Onvoy | 73 | 9% |
| Level 3 Communications | 66 | 8% |
| Verizon Wireless | 46 | 6% |
| Mediacom Telephony Of Illinois | 39 | 5% |
| 63 other carriers | 374 | 48% |
A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. Find which carrier a number is on, or browse the prefix holders.
History of area code 309
- 1957-01-01 Area code 309 went into service.
- 2023-02-24 Area code 861 went into service as an overlay in the same area as 309.
Area codes nearest to 309
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
Overlay codes in the same area
- 861
ZIP codes in area code 309
179 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Peoria, IL | 29 |
| Pekin, IL | 3 |
| Rock Island, IL | 3 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 309 numbers
1,628 FCC complaints are on file for 1,308 numbers in 309, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 87 |
| 2024 | 72 |
| 2025 | 70 |
Other area codes in Illinois
Illinois is one state with 17 area codes in the NANPA table. 309 is one of them.
Next to 309 in the numbering table
These are the codes just before and after 309 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 309 was first assigned in Illinois. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in Illinois next to a 309 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 309
Where is area code 309?
NANPA assigns area code 309 to Illinois, United States.
In which state does area code 309 sit?
Illinois. 309 is one of 17 area codes the NANPA table assigns to the state.
Which places does area code 309 cover?
The places with the most ZIP codes among the rate centers in 309 are Peoria, IL, Pekin, IL and Rock Island, IL. The rate center list on this page shows all of them.
Who owns area code 309?
NANPA assigns area codes. Within 309, Frontier North holds the most prefixes, 99 prefixes or 13%.
Which time zone does 309 use?
The NANPA NPA report lists the time zone for 309 as Central (C).
What year did 309 enter service?
The NANPA NPA report gives an in-service date of 1957-01-01, so 309 has been in use since 1957.
Does area code 309 have an overlay?
Yes. 861 (in service 2023-02-24) shares the same area with 309, so numbers from all of them are local to each other.
Which area codes are nearest to 309?
The area codes closest to 309, measured between the centers of the ZIP code places they serve, are 447 (about 74 miles), 217 (about 75 miles), 815 (about 78 miles), 779 (about 82 miles) and 331 (about 110 miles).
How many prefixes does area code 309 have?
NANPA's report dated 2026-10-17 lists 780 prefixes in service in 309, spread over 171 rate centers and 69 holders.
Are there complaints about 309 numbers?
The FCC data on file has 1,628 complaints for 1,308 numbers in 309. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.