W CHICAGO prefixes in area code 331
NANPA records 8 assigned NXX blocks to rate center W CHICAGO in area code 331, 3.6% of the 224 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 5 holders hold those blocks, the largest being ONVOY, LLC (3), NEW CINGULAR WIRELESS PCS, LLC - IL (2), PEERLESS NETWORK OF ILLINOIS, LLC - IL (1). The earliest assignment on record here is 2007-10-17 and the most recent 2026-02-02. 8 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area code 630 – overlay codes cover the same geography, so a rate center is served by all of them.
Prefixes assigned here
| Prefix | Holder of record | Assigned | Pooled | In service |
|---|---|---|---|---|
| 331-232 | AT&T NEW CINGULAR WIRELESS PCS, LLC - IL | 2017-08-08 | yes | yes |
| 331-240 | Peerless PEERLESS NETWORK OF ILLINOIS, LLC - IL | 2013-04-10 | yes | yes |
| 331-344 | Onvoy ONVOY, LLC | 2026-02-02 | yes | yes |
| 331-465 | AT&T NEW CINGULAR WIRELESS PCS, LLC - IL | 2007-10-17 | yes | yes |
| 331-703 | T-Mobile T-MOBILE USA, INC. | 2013-10-24 | yes | yes |
| 331-800 | Onvoy ONVOY, LLC | 2017-09-29 | yes | yes |
| 331-837 | TON80 COMMUNICATIONS, LLC | 2022-01-07 | yes | yes |
| 331-871 | Onvoy ONVOY, LLC | 2016-02-17 | yes | yes |
The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.
Who holds the blocks
| Holder | Brand | Blocks | Share here |
|---|---|---|---|
| ONVOY, LLC | Onvoy | 3 | 37.5% |
| NEW CINGULAR WIRELESS PCS, LLC - IL | AT&T | 2 | 25% |
| PEERLESS NETWORK OF ILLINOIS, LLC - IL | Peerless | 1 | 12.5% |
| T-MOBILE USA, INC. | T-Mobile | 1 | 12.5% |
| TON80 COMMUNICATIONS, LLC | – | 1 | 12.5% |
Same rate center in other codes
Overlay codes cover the same geography, so one rate center is served by all of them.
Frequently asked
Which prefixes belong to W CHICAGO in area code 331?
8 blocks: 232, 240, 344, 465, 703, 800, 837, 871. The table above gives the holder of each.
Which carriers have numbers in W CHICAGO?
ONVOY, LLC (3 blocks), NEW CINGULAR WIRELESS PCS, LLC - IL (2 blocks), PEERLESS NETWORK OF ILLINOIS, LLC - IL (1 block), T-MOBILE USA, INC. (1 block), TON80 COMMUNICATIONS, LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.
Is W CHICAGO a city?
It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.