Prefix 312-448 — Chicago Zone 01, IL

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

Area code
312
Prefix (NXX)
448
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
2011-08-02
LATA
358

Numbers in the 312-448 prefix are registered to the Chicago Zone 01 rate center in IL, inside area code 312. The prefix is the second block of a ten-digit US number (312-448-XXXX) and pins the number to a billing locality.

NANPA's central-office code records list CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL (OCN 6333) as the code holder, assigned August 2, 2011. Because 312-448 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

The rate center lies in the Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area. The serving LATA is 358. Local time follows the Central zone.

Spoofing means this prefix on your screen doesn't guarantee a Chicago Zone 01 caller. Verify independently before trusting a request for money or data.

Neighboring prefixes

Prefixes adjacent to 312-448
PrefixRate centerCode holder
312-445 Chicago Zone 01 ILLINOIS BELL TEL CO
312-446 Chicago Zone 01 T-MOBILE USA, INC.
312-447 Chicago Zone 01 ILLINOIS BELL TEL CO
312-449 Chicago Zone 01 WAVENATION, LLC
312-450 Chicago Zone 01 NEW CINGULAR WIRELESS PCS, LLC - IL
312-451 Chicago Zone 01 T-MOBILE USA, INC.

FAQ

Where is 312-448 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 312-448 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 312-448 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.