Prefix 312-219 — Chicago Zone 01, IL

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

Area code
312
Prefix (NXX)
219
Rate center
Chicago Zone 01
State
Illinois
Time zone
Central
Code holder
BANDWIDTH.COM CLEC, LLC - IL
OCN
984E
Pooled
Yes (thousands-block pooling)
Assigned
2012-04-10
LATA
358

Numbers in the 312-219 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 (312-219-XXXX) and pins the number to a billing locality.

Code-holder of record: BANDWIDTH.COM CLEC, LLC - IL (OCN 984E), assigned April 10, 2012. The prefix is pooled: its ten thousands-blocks can be shared among several carriers, so different 312-219 numbers may be served by different companies.

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 312-219
PrefixRate centerCode holder
312-216 Chicago Zone 01 FIRST COMMUNICATIONS, LLC
312-217 Chicago Zone 01 T-MOBILE USA, INC.
312-218 Chicago Zone 01 NEW CINGULAR WIRELESS PCS, LLC - IL
312-220 Chicago Zone 01 ILLINOIS BELL TEL CO
312-221 Chicago Zone 01 T-MOBILE USA, INC.
312-222 Chicago Zone 01 ILLINOIS BELL TEL CO

FAQ

Where is 312-219 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 312-219 numbers?

BANDWIDTH.COM CLEC, LLC - 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 312-219 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.