312 Area Code

Area Code	312
State	Illinois
Country	United State
Code Type	General Purpose Code
In Service	Yes
Timezone	Central Standard Time (CST)
Overlay Complex	312/872
Assignment Date	01-JAN-47
In Service Date	01-JAN-47
Area Code	312

What is the 312 Area Code?

Area code 312 is located in Illinois, within United State, serving the region's residents and businesses. The 312 area code was first assigned in 01-JAN-47 and has been in service since 01-JAN-47.

The 312 area code is part of an overlay complex, which includes the area codes 312/872. These codes all serve the same geographic region.

Further Details on the 312 Area Code

Where is the 312 Area Code Located?

Area code 312 serves the entire state of Illinois in United State, providing phone services to both residential and business users. It covers urban, suburban, and rural areas alike, ensuring reliable communication across the region.

What time zone is area code 312 in?

Area code 312 is located in the Central Standard Time (CST) time zone. This designation indicates the predominant time zone for calls made within this area code.

When was area code 312 assigned and put into service?

Area code 312 was officially assigned on 01-JAN-47, signifying its designation for use in telecommunications, and it became operational on 01-JAN-47, allowing callers to begin using this area code for their dialing needs.

Is the 312 Area Code Still Active?

Yes, the 302 area code is still active and in service. It is the primary area code for all landline and mobile phones registered in Delaware. There are no overlay codes currently in place for the state.

What are the dialing requirements for making calls with area code 312?

For local calls within area code 312, the required dialing pattern is 1+10D. For toll calls, you'll need to dial 1+10D , where "D" indicates the number of digits to dial. When calling foreign NPAs from area code 312, local calls require 1+10D, and toll calls use 1+10D.

Data Sources: NANPA Area Code, U.S. Area Code Map