618 Area Code: What Cities And Regions Does It Serve?

# 618 Area Code: A Comprehensive Guide to Southern Illinois

## Introduction

The 618 area code serves a large portion of Southern Illinois. If you've received a call from a 618 number, it's likely originating from this region of the state. This guide will provide a detailed overview of the cities, counties, and geographical areas covered by the 618 area code, helping you understand its scope and location.

## What Areas Does the 618 Area Code Cover?

The 618 area code covers a significant portion of Southern Illinois. It includes a diverse range of cities, counties, and geographical areas. Here's a breakdown:

### Major Cities in the 618 Area Code

*   **Alton:** A city located in Madison County, known for its historical significance and riverfront views.
*   **Belleville:** A major city in St. Clair County, serving as a hub for the region.
*   **Carbondale:** Home to Southern Illinois University, Carbondale is a vibrant college town.
*   **Centralia:** A city spanning Marion and Clinton counties, known for its central location in Southern Illinois.
*   **Collinsville:** Located in Madison and St. Clair counties, Collinsville is known for its rich history and the famous Cahokia Mounds.
*   **Edwardsville:** The county seat of Madison County, Edwardsville is a growing city with a strong sense of community.
*   **Fairview Heights:** A commercial center in St. Clair County, offering a variety of shopping and dining options.
*   **Marion:** A city in Williamson County, serving as a retail and commercial hub for the region.
*   **Mount Vernon:** Located in Jefferson County, Mount Vernon is a regional center for healthcare and business.
*   **O'Fallon:** A rapidly growing city in St. Clair County, known for its family-friendly atmosphere.

### Counties Served by the 618 Area Code

The 618 area code encompasses a wide range of counties in Southern Illinois. These include:

*   Alexander County
*   Bond County
*   Calhoun County
*   Clark County (Partial)
*   Clay County
*   Clinton County
*   Crawford County
*   Edwards County
*   Effingham County (Partial)
*   Fayette County
*   Franklin County
*   Gallatin County
*   Greene County
*   Hamilton County
*   Hardin County
*   Jackson County
*   Jasper County
*   Jefferson County
*   Jersey County
*   Johnson County
*   Lawrence County
*   Macoupin County
*   Madison County
*   Marion County
*   Massac County
*   Monroe County
*   Montgomery County
*   Perry County
*   Pope County
*   Pulaski County
*   Randolph County
*   Richland County
*   St. Clair County
*   Saline County
*   Union County
*   Wabash County
*   Washington County
*   Wayne County
*   White County
*   Williamson County

### Geographical Region

The 618 area code primarily covers the southern portion of Illinois. It spans from the Greater St. Louis metropolitan area in the west to the Indiana border in the east, and south to the Kentucky border. This region includes a mix of urban centers, rural communities, and agricultural areas. The landscape varies from the bluffs along the Mississippi River to the rolling hills and forests of the Shawnee National Forest. The southern Illinois region is characterized by its unique blend of cultural influences, historical sites, and natural beauty.

## History of the 618 Area Code

The 618 area code was created as one of the original 86 area codes in North America in 1947. It originally covered the entire southern portion of Illinois. As the population grew and the demand for phone numbers increased, the 618 area code was split in 1996, creating the 779 area code as an overlay.

### The 1996 Split

In 1996, to accommodate the increasing demand for telephone numbers, a geographic split was implemented. The northern and western portions of the original 618 territory were assigned to the new 618 area code, while the southern and eastern areas retained the 618 area code. This split helped to alleviate the strain on available phone numbers and ensure continued service for the region.

### Overlay with the 779 Area Code

To further address the growing need for phone numbers, the 779 area code was introduced as an overlay to the 618 area code in 2017. This means that the 779 area code covers the same geographic area as the 618 area code. As a result, ten-digit dialing (area code + seven-digit number) became mandatory for all calls within the 618 and 779 area codes. This overlay ensures that there are enough phone numbers available for the region without the need for another geographic split.

## Why Ten-Digit Dialing is Required in the 618 Area Code

With the implementation of the 779 area code overlay, ten-digit dialing became mandatory in the 618 region. This means that callers must dial the area code plus the seven-digit phone number for all calls, even local ones. The transition to ten-digit dialing is a crucial step in ensuring the efficient allocation and utilization of phone numbers within the area.

The reasons for this requirement are twofold:

1.  **Preventing Exhaustion of Phone Numbers:** The overlay allows for the allocation of additional phone numbers without exhausting the existing supply in the 618 area code.
2.  **Ensuring Seamless Communication:** Ten-digit dialing ensures that all calls are routed correctly, regardless of whether the number is assigned to the 618 or 779 area code.

## Key Takeaways

The 618 area code covers a significant portion of Southern Illinois, including numerous cities and counties. Understanding the areas served by this area code can help you identify the origin of phone calls and better comprehend the geography of Southern Illinois. The implementation of the 779 overlay area code and the mandatory ten-digit dialing are important measures to ensure the continued availability of phone numbers in the region.

## FAQ

### What is the 618 area code?

The 618 area code is a telephone area code that serves the southern portion of Illinois.

### Where is the 618 area code located?

The 618 area code covers a large area in Southern Illinois, stretching from the St. Louis metropolitan area to the Indiana border, and south to the Kentucky border.

### Which cities are in the 618 area code?

Major cities in the 618 area code include Alton, Belleville, Carbondale, Centralia, Collinsville, Edwardsville, Fairview Heights, Marion, Mount Vernon, and O'Fallon.

### What counties are covered by the 618 area code?

The 618 area code covers all or part of numerous counties in Southern Illinois, including Madison, St. Clair, Jackson, Williamson, and Jefferson counties, among others.

### Why is ten-digit dialing required in the 618 area code?

Ten-digit dialing is required due to the overlay of the 779 area code, which shares the same geographic area as the 618 area code. This ensures that all calls are routed correctly.

### What is the 779 area code?

The 779 area code is an overlay area code that covers the same geographic area as the 618 area code in Southern Illinois.

### When did ten-digit dialing become mandatory in the 618 area code?

Ten-digit dialing became mandatory in the 618 area code when the 779 area code was introduced as an overlay, ensuring that calls are routed correctly within the shared geographic area.

## Conclusion

The 618 area code is an integral part of Southern Illinois, encompassing a diverse range of communities and regions. From bustling cities to rural landscapes, the 618 area code connects millions of residents and businesses. Understanding the history, geography, and requirements of this area code, including the ten-digit dialing mandate, is essential for effective communication in the region. Whether you're a long-time resident or new to the area, knowing the 618 area code is key to staying connected in Southern Illinois.

If you have any further questions or need additional information about the 618 area code, feel free to reach out to your local telecommunications provider or consult official resources for the most up-to-date details.