Area Code Atlas

Initial assignment of area codes 317 and 812 in Indiana

In 1947, AT&T published the first configuration of numbering plan areas. Indiana was assigned two area codes: 317 for the northern two-thirds and 812 for the southern third. Area code 317 was introduced as one of the original North American area codes, covering the northern two-thirds of Indiana, and was part of the initial nationwide numbering plan.

Indiana divided into area codes 317 and 812

Indiana was divided into two numbering plan areas in 1947 as part of the original North American Numbering Plan. Area code 812 was assigned to the southern third of the state, while 317 covered the northern two-thirds.

Area code 219 created from northern part of 317

Area code 219 was created in 1948 from the northern third of the original 317 area, including cities such as Gary and South Bend. This split was the first change to Indiana's original area code configuration.

NANP-Split of 317 (Indiana) Numbering Plan Area (NPA)

Area code 765 split from 317

Area code 765 was created on February 1, 1997, splitting from 317 to serve most of the territory outside the inner Indianapolis metropolitan area. This was Indiana's first new area code in 49 years, addressing the growing demand for telephone numbers in central Indiana.

Mandatory 10-digit dialing implemented for area codes 317 and 765

Mandatory 10-digit dialing became effective on June 28, 1997, for both area codes 317 and 765 following the split. Callers in the region were required to use the full area code for all calls, reflecting the new numbering plan boundaries.

NPA 463 overlay on 317 announced

NPA 463 to Overlay NPA 317 (Indiana)

Overlay of area code 463 in Indianapolis

Area code 463 was added as an overlay to area code 317 on March 15, 2016, initiating a permissive dialing period allowing both seven- and ten-digit dialing.

Permissive dialing period begins for 317/463 overlay

A permissive dialing period began on March 15, 2016, allowing both seven- and ten-digit dialing for calls within the 317/463 region as the overlay was implemented. This period was implemented in the Indianapolis area and central Indiana.

NPA 463 overlay on 317 announced

NPA 463 to Overlay NPA 317 (Indiana)

Mandatory ten-digit dialing planned for 317/463

Mandatory ten-digit dialing was originally scheduled to begin on September 15, 2016, for the 317/463 overlay area in central Indiana.

Mandatory ten-digit dialing implemented for 317/463

The deadline for mandatory ten-digit dialing in the 317/463 overlay area was extended to October 15, 2016, when ten-digit dialing became mandatory.

Area code 463 overlaid on 317

On November 15, 2016, area code 463 was introduced as an overlay to area code 317 in central Indiana to provide additional numbering resources.