One of the original 1947 North American area codes, 217 serves central Illinois including the state capital Springfield. Since 2021 it has been overlaid by area code 447 across the same geography.
The essentialsNumbering data · NumberResearch · as of 2026-09-18
Place
Central Illinois (Springfield)
Type
geographic
Status
in service
In service since
1947
Projected exhaust
2046 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 217 is
Central Illinois - Springfield/Sangamon County, the Champaign-Urbana metro, Decatur, and surrounding rural counties.
Representative subset; the NPA covers many additional smaller municipalities.
B · Relationships
How it relates to other codes
The codes 217 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?
Overlay · 2021447Central Illinois (overlay of 217)All-services overlay of 217 (ICC-approved 2006, activated 2021).
Spawned · 1951618Southern Illinois (Metro East)1951 boundary shift reassigned most of the southern Metro East from 217 to 618; further Metro East moved in 1954.
Spawned · 1956309West-Central Illinois (Peoria)Northern 217 territory (Peoria, Bloomington-Normal) reorganized in Sept 1956 toward the new 309 NPA (formally split from 815 in 1957).
What's changing. Overlaid by 447 (all-services overlay) since 2021; ten-digit dialing mandatory.
C · History
How 217 got here
1947
Established as one of the original North American area codes, covering central Illinois including much of the Metro East.
Source: Wikipedia - Area code 217
1951
Boundary shift reassigned most of the southern Metro East region to area code 618.
Source: Wikipedia - Area code 217
1956
Northern portion (Peoria, Bloomington-Normal) reorganized toward the new 309 NPA.
Source: Wikipedia - Area code 217
2021-02-27
Ten-digit dialing became mandatory ahead of the 447 overlay.
Source: Wikipedia - Area codes 217 and 447
2021-03-27
Overlay code 447 became available for assignment.
Source: Wikipedia - Area codes 217 and 447
D · Capacity
How full it is
Prefixes assigned
800
Prefixes available
0
Thousands-blocks assigned
3,250
Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.
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.
North American Numbers