Ameritech Illinois
Holding: AT&T Inc
1998-07-14
2017-02-17
About AT&T Illinois
AT&T Illinois is the Illinois operating company of AT&T Inc., functioning as a Regional Bell Operating Company (RBOC) providing local exchange and related telecommunications services within the state. It primarily serves consumers and businesses with home internet, fiber optic services, and channel services for intrastate connectivity. As part of the former Illinois Bell Telephone Company, it operates within AT&T's broader national footprint, holding state-level Operating Company Numbers (OCNs) and managing thousands of number blocks.
- Parent: AT&T Inc.
- Services: local exchange, fiber internet, channel services
Sources: AT&T Carrier Mills, IL | Home Services, Plans & Availability · AT&T ILLINOIS GUIDEBOOK PART 15 - Channel Services · AT&T in Illinois - Home & Business Services
Toll-free side: Related toll-free RespOrg: AT&T (code BSSB1). View on resporgs.com →
Headquarters: Hoffman Estates, IL
From Ameritech Illinois (OCN 9329), the largest member of the Ameritech Illinois group.
Carrier website
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Block portfolio at a glance
Block assignments by year
Member OCNs
2 OCNs roll up under Ameritech Illinois.
| OCN | Company name on file | HQ | Type | Total | Recent |
|---|---|---|---|---|---|
| 9329 | Ameritech Illinois | Hoffman Estates, IL | Regional Bell Operating Company | 6,645 | · |
| 9327 | Ameritech Wisconsin | Hoffman Estates, IL | Regional Bell Operating Company | 2,021 | · |