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Area code 312

Area code 312 serves Illinois, including Chicago Zone 01, Wheeling and Hinsdale (Central time). It has been in service since January 1, 1947 and shares its area with 872.

Numbers starting with 312 drew 1,232 reports to the FTC from Aug 14, 2026 to Nov 11, 2026 and 1,146 complaints to the FCC since November 2023. The number on your screen can be faked, so a 312 number proves nothing about where a call came from.

Location
IllinoisChicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area
Time zone
Central
In service since
January 1, 1947
Overlay
Same area as 872
Local calls
Dial 1 + 10 digits
Exchanges in use
784 of 792held by 36 carriers
Projected to run out
4Q 2048NANPA forecast 2026.2

Complaints about 312 numbers

Reports where the number on the consumer's caller ID (or, for the FCC, the number the caller asked them to call back) starts with 312. These are counts of what people reported; the agencies do not verify them.

FTC reports, Aug 14, 2026 to Nov 11, 2026

1,232

FCC complaints since November 2023

1,146

Different 312 numbers reported

1,703

FCC complaints naming a 312 number, by month

November 2023 to October 2026. Source: FCC Consumer Complaints Data.

Show as a table
MonthComplaints
November 202351
December 202360
January 202451
February 202425
March 202427
April 202418
May 202420
June 202458
July 202477
August 202441
September 202476
October 2024137
November 202471
December 202417
January 202547
February 202521
March 202518
April 202515
May 202519
June 202524
July 202516
August 202513
September 202512
October 20251
November 20256
December 202520
January 202616
February 202616
March 202619
April 202613
May 202611
June 202615
July 202617
August 202614
September 202633
October 202633

What people said 312 calls were about

Subjects picked in FTC reports, August 14, 2026 to November 11, 2026. 576 of 1,232 reports were robocalls.

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SubjectReports
Other621
Dropped call or no message198
Reducing your debt (credit cards, mortgage, student loans)109
Calls pretending to be government, businesses, or family and friends103
Medical and prescriptions71
Warranties and protection plans13

Most reported 312 numbers

Numbers with at least five reports from three or more places in the last twelve months. Many of them are likely spoofed.

Places served by 312

NANPA lists 8 rate centers for 312. A rate center is the town or district a block of numbers is tied to for billing; sorted here by how many exchanges each holds.
  • Chicago Zone 01746
  • Wheeling12
  • Hinsdale11
  • La Grange8
  • Northbrook3
  • Roselle2
  • Chicago Zone 041
  • Chicago Zone 071

Phone companies holding 312 exchanges

Each exchange (the three digits after the area code) is assigned to one carrier. 53% of these exchanges are pooled: their numbers are handed out in blocks of 1,000 to other carriers, so the holder below is not always the company serving a given number.

Exchanges held, top 8 of 36 carriers

NANPA central office code assignments, file of November 11, 2026.

Show as a table
Carrier (legal name)Exchanges
Illinois Bell Tel CO334
New Cingular Wireless PCS, LLC - IL82
T-Mobile USA, Inc.64
Cellco Partnership dba Verizon Wireless - IL54
Level 3 Communications, LLC - IL33
Mcimetro Access Transmission Services LLC33
Spok, Inc.33
Teleport Communications America, LLC - IL22

When today's 312 exchanges were assigned

Exchanges still assigned, by year of assignment. Exchanges returned since are not counted.

Show as a table
YearExchanges
200128
20026
20032
20043
20052
20065
20072
20087
20091
20104
20118
201215
201315
201425
201519
201619
201714
20186
20196
20203
20222
20232
20241
20252
20262

Check a 312 number

A check shows the carrier and rate center of the number's exchange and every FTC and FCC report about that exact number. Why the number on screen can be fake.

Other area codes in Illinois

NANPA area code database and central office code file of November 11, 2026; FCC complaints November 1, 2023 to November 11, 2026; FTC reports August 14, 2026 to November 11, 2026. How the data is used.

Official sources (7)Show