312 Area Code: Chicago, Illinois
From the North American Numbering Plan Administrator (NANPA), checked October 13, 2026.
312 is a Chicago, Illinois area code. NANPA lists one rate center for it, Chicago Zone 01, and 872 also serves its area.
Local 312 numbers available
None found
Twilio's number search found no local 312 numbers that can take calls, checked October 15, 2026. CallFlux buys its tracking numbers through Twilio. We run this search at most once a day, and one search lists at most 30 numbers. Numbers come and go, so a search in the CallFlux dashboard shows what is available at that moment.
312 area code at a glance
Places the 312 area code covers
“The 312 NPA and 773 NPA serve the City of Chicago; the 773 NPA also serves O’Hare International Airport and Midway International Airport.”
NANPA's map of 312 is in Planning Letter PL-392 (PDF).[12]
Rate centers NANPA lists for 312
NANPA's rate center report lists one rate center for 312, as of October 13, 2026.[14]
- Chicago Zone 01
Area codes that share the 312 area
In an overlay, more than one area code serves the same area. NANPA lists 312 in the 312/872 overlay. So 872 serves the same area as 312.[3]
“The new 872 NPA will serve the same geographic area currently served by the existing 312 and 773 NPAs.”
Get a local 312 tracking number
CallFlux tracking numbers are picked by area code. In the CallFlux dashboard you type 312, search the numbers available in it and choose one. Calls to that number forward to the phone you set, and you can record them, assign the number to a campaign and swap it onto your website, so each call shows which ad or page it came from.
A local tracking number is $1.15 a month, on top of a CallFlux plan.
Frequently asked questions
Where is the 312 area code?
312 is a Chicago, Illinois area code. NANPA lists one rate center for it, Chicago Zone 01, and 872 also serves its area.
What area codes share the 312 area?
NANPA lists 312 in the 312/872 overlay. So 872 serves the same area as 312.
What time zone is the 312 area code in?
NANPA lists Central as the predominant time zone for 312.
How do you dial a local call in the 312 area code?
NANPA lists 1 + 10 digits as the predominant way to dial both local and toll calls within 312.
When did the 312 area code start?
NANPA lists January 1, 1947 as the date 312 was placed in service.
Can I get a local 312 phone number for my business?
Our latest search, on October 15, 2026, found no local 312 numbers. Numbers come and go, so search 312 again in the CallFlux dashboard. A local tracking number is $1.15 a month, on top of a CallFlux plan.
Sources
Every fact on this page, the words it rests on and the date it was checked. NANPA writes NPA for an area code.
[1] NANPA lists 312 as an area code in Illinois.
“LOCATION: IL”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[2] NANPA lists January 1, 1947 as the date 312 was placed in service.
“IN_SERVICE_DT: 01-Jan-1947”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[3] NANPA lists 312 as part of the 312/872 overlay.
“OVERLAY_COMPLEX: 312/872”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[4] NANPA lists Central as the predominant time zone of 312.
“TIME_ZONE: C”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[5] NANPA's TIME_ZONE field gives a code's predominant time zone or zones.
“Predominant time zone(s) for NPA”
NANPA NPA Database field definitions · checked October 13, 2026
[6] In NANPA's field definitions, C stands for Central.
“C-Central”
NANPA NPA Database field definitions · checked October 13, 2026
[7] NANPA lists 1 + 10 digits as the predominant way to dial a local call within 312.
“HOME_NPA_LOCAL_CALLS: 1+10D”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[8] NANPA's HOME_NPA_LOCAL_CALLS field gives the predominant dialing pattern for local calls.
“Predominant dialing pattern on Home NPA Local Calls”
NANPA NPA Database field definitions · checked October 13, 2026
[9] NANPA lists 1 + 10 digits as the predominant way to dial a toll call within 312.
“HOME_NPA_TOLL_CALLS: 1+10D”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[10] NANPA's HOME_NPA_TOLL_CALLS field gives the predominant dialing pattern for toll calls.
“Predominant dialing pattern on Home NPA Toll Calls”
NANPA NPA Database field definitions · checked October 13, 2026
[11] In NANPA's field definitions, 1+10D stands for 1 + 10 digits.
“1+10D - one plus ten digits”
NANPA NPA Database field definitions · checked October 13, 2026
[12] NANPA's database points to Planning Letter PL-392 for a map of 312.
“MAP: 392”
NANPA NPA Database (file dated October 13, 2026) · checked October 13, 2026
[13] NANPA's rate center report puts 312's only rate center in the Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area.
“Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area”
NANPA NPA Rate Center Report (created October 13, 2026) · data · checked October 13, 2026
[14] NANPA's rate center report lists 1 rate center for 312.
“CHICAGO ZONE 01”
NANPA NPA Rate Center Report (created October 13, 2026) · data · checked October 13, 2026
[15] NANPA describes 312 and 773 as the City of Chicago, with 773 also serving both airports.
“The 312 NPA and 773 NPA serve the City of Chicago; the 773 NPA also serves O’Hare International Airport and Midway International Airport.”
NANPA Planning Letter PL-392 (August 10, 2009) · checked October 13, 2026
[16] 872 serves the same area as 312 and 773.
“The new 872 NPA will serve the same geographic area currently served by the existing 312 and 773 NPAs.”
NANPA Planning Letter PL-392 (August 10, 2009) · checked October 13, 2026
[17] NANPA's glossary uses NPA, Numbering Plan Area, for an area code.
“Numbering Plan Area (Area Code)”
NANPA glossary · checked October 13, 2026