North American Numbers Source-cited · ownership disclosed
Area code
317
In service
United States · since 1947

Indianapolis

One of the original 1947 North American area codes, serving Indianapolis and the surrounding central Indiana counties. Since 2016 it has shared its territory with overlay code 463, requiring ten-digit dialing.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Indianapolis
Type
geographic
Status
in service
In service since
1947
Projected exhaust
2058 Q2

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 317 is

Marion County and surrounding central Indiana counties: Boone, Hancock, Hamilton, Hendricks, Johnson, Madison, Morgan, and Shelby (all or parts)..

Communities served wholly or partly by 317:

IndianapolisCarmelFishersNoblesvilleGreenwoodAnderson

Coverage of outer counties (e.g. Madison) is partial; some communities carry 765.

B · Relationships

How it relates to other codes

The codes 317 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Spawned · 1997 765 Central Indiana (outside Indianapolis) On Feb 1, 1997 the outer central-Indiana territory of 317 split off to the new 765; 317 retained the greater Indianapolis area.
Overlay · 2016 463 Indianapolis (overlay) All-services overlay of the 317 area; 463 spells IND on the keypad.
Spawned · 1948 219 Gary In 1948 the northern portion of the original 317 territory was reassigned to new area code 219.
What's changing. Overlaid with 463 since 2016; ten-digit dialing mandatory.
C · History

How 317 got here

1947
Area code 317 established as one of the original NANP area codes, initially covering roughly the northern two-thirds of Indiana.
Source: Wikipedia
1948
317 reduced to central Indiana; northern region reassigned to new area code 219.
Source: Wikipedia
1997-02-01
Outer central-Indiana territory split off to area code 765; 317 retained metro Indianapolis.
Source: Wikipedia
2016-03-15
Overlay area code 463 entered service across the 317 territory.
Source: Wikipedia
2016-10-15
Mandatory ten-digit dialing began.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
800
Prefixes available
0
Thousands-blocks assigned
3,125

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 317 with another code →
Sources
Wikipedia ↗
Area code 317
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.