Exhibit 21
PRINCIPAL SUBSIDIARIES OF
AT&T INC., AS OF DECEMBER 31, 2020
2020 AT&T INC. REPORT TO STOCKHOLDERS
SECURITIES AND EXCHANGE COMMISSION ("SEC")
FORM 10-K filed February 25, 2021

Legal Name | State of Incorporation/Formation | Conducts Business Under
Illinois Bell Telephone Company, LLC | Illinois | AT&T Illinois; AT&T Wholesale
Indiana Bell Telephone Company, Incorporated | Indiana | AT&T Indiana; AT&T Wholesale
Michigan Bell Telephone Company | Michigan | AT&T Michigan; AT&T Wholesale
Nevada Bell Telephone Company | Nevada | AT&T Nevada; AT&T Wholesale
Pacific Bell Telephone Company | California | AT&T California; AT&T Wholesale; AT&T DataComm
SBC Long Distance, LLC | Delaware | AT&T Long Distance
AT&T Teleholdings, Inc. | Delaware | AT&T Midwest; AT&T West; AT&T East
Southwestern Bell Telephone Company | Delaware | AT&T Arkansas; AT&T Kansas; AT&T Missouri; AT&T Oklahoma; AT&T Texas; AT&T Southwest; AT&T DataComm; AT&T Wholesale
The Ohio Bell Telephone Company | Ohio | AT&T Ohio; AT&T Wholesale
Wisconsin Bell, Inc. | Wisconsin | AT&T Wisconsin; AT&T Wholesale
AT&T Services, Inc. | Delaware | AT&T Services; AT&T Labs

AT&T Corp. | New York | AT&T Corp.; ACC Business; AT&T Wholesale; AT&T Business Solutions; AT&T Advanced Solutions; AT&T Diversified Group; AT&T Mobile and Business Solutions
Teleport Communications America, LLC | Delaware | same
BellSouth, LLC | Georgia | AT&T South
BellSouth Telecommunications, LLC | Georgia | AT&T Alabama AT&T Florida AT&T Georgia AT&T Kentucky AT&T Louisiana AT&T Mississippi AT&T North Carolina AT&T South Carolina AT&T Tennessee AT&T Southeast
AT&T Mobility LLC | Delaware | same
AT&T Mobility II LLC | Delaware | same
New Cingular Wireless PCS, LLC | Delaware | AT&T Mobility
Cricket Wireless LLC | Delaware | same
AT&T Communications, LLC | Delaware | same
AT&T Latin America, LLC | Delaware | same
AT&T Comunicaciones Digitales, S . de R.L. de C.V. | Mexico City | same
DIRECTV, LLC | California | same
DIRECTV Enterprises, LLC | Delaware | same
Vrio Corp. | Delaware | same
DIRECTV Latin America, LLC | Delaware | same
Sky Serviços de Banda Larga Ltda. | Brazil | Sky Brasil

DIRECTV Colombia Ltda. | Colombia | same
DIRECTV Argentina S.A. | Argentina | same
Warner Media, LLC | Delaware | same
Home Box Office, Inc. | Delaware | HBO Global Licensing
Turner Broadcasting System, Inc. | Delaware | Turner
Warner Bros. Entertainment Inc. | Delaware | Warner-Grandview Music Warner Bros. Warner Bros. International Film Acquisitions Warner Bros. International Cinemas Warner Bros. Entertainment Group Warner Bros. Global Insights & Analytics
Historic TW Inc. | Delaware | same
Warner Media Content Holdings, L.P. | Delaware | same
WarnerMedia Direct, LLC | Delaware | same
Warner Communications LLC | Delaware | same
Xandr Inc. | Delaware | same