quality:corruption, quality:correction
Purchase of former parent and acquisitions (2005–2013)

On November 18, 2005, SBC Communications purchased its former parent, AT&T Corporation for $16 billion. After this purchase, SBC adopted the better-known AT&T name and brand, with the original AT&T Corporation still existing as the long-distance landline subsidiary of the merged company. The current AT&T Inc. claims the original AT&T Corporation's history (dating to 1877) as its own, but retains SBC's pre-2005 corporate structure and stock price history. As well, all SEC filings before 2005 are under SBC, not AT&T.

AT&T made an attempt in 2011 to purchase T-Mobile for a $39 billion stock and cash offer. The bid was withdrawn after the takeover company was faced with significant regulatory and legal hurdles, along with heavy resistance from the U.S. government. As per the original acquisition agreement, T-Mobile received $3 billion in cash as well as access to $1 billion worth of AT&T-held wireless spectrum.

In September 2013, AT&T announced it would expand into Latin America through a collaboration with América Móvil. In December 2013, AT&T announced plans to sell its Connecticut wireline operations to Stamford-based Frontier Communications.

AT&T acquired BellSouth Corporation on December 29, 2006, following FCC approval. The transaction consolidated ownership and management of Cingular Wireless. AT&T rebranded its wireless retail stores from Cingular to AT&T in January 2007.