AT&T Michigan
Holding: AT&T Inc
2001-01-15
2019-10-31
About AT&T Michigan
AT&T Michigan (The Michigan Bell Telephone Company) is a Regional Bell Operating Company (RBOC) subsidiary of AT&T Inc. that provides wireline, fiber, wireless, and fixed wireless internet services across Michigan. The carrier serves both consumer and business customers through retail and wholesale channels, operating as part of AT&T's broader national network covering over 99% of Americans.
- Parent: AT&T Inc.
- Headquarters: Hoffman Estates, IL
- Services: wireline local exchange, fiber broadband (AT&T Fiber), fixed wireless internet (AT&T Internet Air), wireless voice and data, wholesale/interexchange
Sources: AT&T Michigan Guidebook Part 1 · Michigan Public Service Commission - Interexchange and Competitive Access Providers List (April 24, 2026) · How AT&T is Investing in Michigan
Toll-free side: Related toll-free RespOrg: AT&T (code BSSB1). View on resporgs.com →
Headquarters: Hoffman Estates, IL
Carrier website
att.com: opens in a new tab
Block portfolio at a glance
By age
- Recent (0). Last 18 mo
- Medium (0)
- Old (312)
- Undated (4,723)
Footprint by state
Stronger blue = more blocks issued in that state. ● marks states with activity in the last 18 months.
- Michigan MI · 5,035
Top area codes
Bars show total blocks; red overlay is recent.
Block assignments by year
Member OCNs
1 OCN roll up under AT&T Michigan.
| OCN | Company name on file | HQ | Type | Total | Recent |
|---|---|---|---|---|---|
| 9323 | Ameritech Michigan | Hoffman Estates, IL | Regional Bell Operating Company | 5,035 | · |