618 Area Code — Illinois
618 is a North American Numbering Plan area code for Illinois, the United States. It covers about 1,184,182 people in 320 towns and 333 ZIP codes, including Belleville, East Saint Louis and Granite City.
| Field | Value |
|---|---|
| Area code | 618 |
| Country | United States (+1) |
| State / province | Illinois |
| Type | Standalone (no other NANP code covers the same towns) |
| Time zone | Central |
| Population covered | 1,184,182 |
| Towns covered | 320 |
| ZIP codes | 333 |
| Approx. centre | 38.302, -89.163 |
Where area code 618 is used
Area code 618 is assigned to Illinois, the United States, inside the North American Numbering Plan. Numbers in the code are written (618) NXX-XXXX at home and +1 618 NXX-XXXX when dialled from outside Canada and the United States. Since the NANP moved to 10-digit dialling you must always include the area code, even for a local call.
Towns and cities in area code 618
The 320 towns below are the largest in the 618 footprint, ranked by population. Every one of them links to its own page with the full list of area codes and ZIP codes for that town.
| Town | County | Population | ZIP codes |
|---|---|---|---|
| Belleville | St. Clair County | 93,551 | 5 |
| East Saint Louis | St. Clair County | 40,843 | 7 |
| Granite City | Madison County | 40,404 | 1 |
| Edwardsville | Madison County | 36,371 | 2 |
| O Fallon | St. Clair County | 35,923 | 1 |
| Collinsville | Madison County | 31,648 | 1 |
| Carbondale | Jackson County | 29,747 | 3 |
| Alton | Madison County | 29,543 | 1 |
| Marion | Williamson County | 27,793 | 1 |
| Mount Vernon | Jefferson County | 22,779 | 1 |
| Centralia | Marion County | 19,827 | 1 |
| Waterloo | Monroe County | 18,208 | 1 |
Counties covered
| County | ZIP codes |
|---|---|
| St. Clair County | 30 |
| Madison County | 27 |
| Franklin County | 17 |
| Jackson County | 16 |
| Jefferson County | 13 |
| Clinton County | 12 |
| Randolph County | 12 |
| Wayne County | 12 |
| Williamson County | 12 |
| White County | 11 |
| Washington County | 10 |
| Marion County | 10 |
Nearby area codes
How to dial area code 618
- Within North America: 618 + 7-digit number (618-NXX-XXXX). The leading 1 is optional on a mobile phone and required on most landlines for long-distance.
- From abroad: your country's international prefix, then 1, then 618, then the 7-digit number — for example 00 1 618 NXX-XXXX from most of Europe.
Frequently asked questions
What area code is 618?
618 is a North American Numbering Plan area code assigned to Illinois, the United States. It covers about 1,184,182 people in 320 towns.
Is 618 a US or Canadian area code?
618 is a United States area code. Canada and the United States share the +1 country code, so both are part of the same numbering plan.
What time zone is area code 618 in?
Area code 618 is in the Central time zone.
Do I have to dial 10 digits?
Yes. Every NANP call now requires the area code plus the seven-digit number, even for a local call.