Prefix 312-597 — Chicago Zone 01, IL

NANPA CO code assignment, current as of July 28, 2026.

Area code
312
Prefix (NXX)
597
Rate center
Chicago Zone 01
State
Illinois
Time zone
Central
Code holder
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL
OCN
6333
Pooled
Yes (thousands-block pooling)
Assigned
2016-10-04
LATA
358

A phone number starting 312-597 was issued in the Chicago Zone 01 rate center of IL — part of area code 312.

The assigned code holder is CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL, operating company number 6333, assigned October 4, 2016. This is a pooled prefix — expect numbers within it to be split across more than one carrier in 1,000-number blocks.

A scammer can display 312-597 without ever touching IL. When in doubt, end the call and reach the company or agency through its official website; unwanted robocalls belong in the FTC's fraud report queue.

Chicago Zone 01 is part of the Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area. For routing purposes it sits in LATA 358. Numbers here keep Central time.

Neighboring prefixes

Prefixes adjacent to 312-597
PrefixRate centerCode holder
312-594 Chicago Zone 01 MCIMETRO ACCESS TRANSMISSION SERVICES LLC
312-595 Chicago Zone 01 ILLINOIS BELL TEL CO
312-596 Chicago Zone 01 TELEPORT COMMUNICATIONS AMERICA, LLC - IL
312-598 Chicago Zone 01 ONVOY, LLC
312-599 Chicago Zone 01 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL
312-600 Chicago Zone 01 ONVOY, LLC

FAQ

Where is 312-597 located?

The prefix is assigned to the Chicago Zone 01 rate center in IL, area code 312. It is part of the Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area.

Which company owns 312-597 numbers?

CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL holds the code, but the prefix is pooled — individual thousands-blocks can be assigned to other carriers, and numbers may be ported to any provider.

Is a call from 312-597 safe to answer?

The prefix itself says nothing about the caller. Legitimate Chicago Zone 01 businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.