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312 Area Code — Scam Calls, Location & Who's Calling

Area code 312 serves Illinois in the Central time zone, in service since 1947. The FCC has 5,380 unwanted-call complaints against 3,004 different 312 numbers on record. Look up the exact number that called you below.

Most-reported 312 numbers

Ranked by FCC unwanted-call complaints. Click a number for its full report.

312 unwanted-call complaints, last 12 months

Monthly FCC complaint volume against 312 numbers. Spikes usually mark an active robocall campaign cycling through the code.

Carriers operating in 312

Carriers assigned to 312 prefixes that visitors have looked up so far — resolved from official NPA-NXX assignment records.

  • ILLINOIS BELL TEL COI · 38 prefixes
  • ONVOY, LLCC · 13 prefixes
  • LEVEL 3 COMMUNICATIONS, LLC - ILC · 13 prefixes
  • MCIMETRO ACCESS TRANSMISSION SERVICES LLCC · 10 prefixes
  • BANDWIDTH.COM CLEC, LLC - ILC · 9 prefixes
  • T-MOBILE USA, INC.Wireless · 8 prefixes
  • PEERLESS NETWORK OF ILLINOIS, LLC - ILC · 8 prefixes
  • PAETEC ITEL, LLCC · 5 prefixes

About area code 312

Serves
Illinois
Time zone
Central
In service since
1947-01-01
Overlay
Yes — 10-digit dialing

Source: NANPA numbering records, refreshed weekly.

Spam calls from 312? What to know

Seeing repeated missed calls from 312 numbers you don't recognize is the classic signature of neighbor-spoofing robocall campaigns. The caller isn't necessarily in Illinois — spoofing software displays whatever digits the campaign chooses. Never call unknown numbers back; look them up first, and report unwanted calls to the FCC to build the public record.

Area code 312 FAQs

Where is area code 312?

Area code 312 serves Illinois, in the Central time zone. It is part of an overlay complex, so multiple area codes serve the same territory and 10-digit dialing is required. It has been in service since 1947.

Why do I keep getting calls from 312 numbers?

Robocallers use "neighbor spoofing" — displaying a number with a local area code to make you more likely to answer. A call showing area code 312 may not originate from Illinois at all. Look up the full 10-digit number on this site to see its complaint history before calling back.

Are 312 numbers safe to call back?

Area codes themselves are neither safe nor unsafe — 312 contains millions of legitimate lines alongside any spoofed or spam numbers. The FCC has logged 5,380 unwanted-call complaints against 3,004 distinct 312 numbers in our current data window. Check the specific number's report page before returning a missed call.