KDDI

KDDI Corporation
	Headquarters in Iidabashi, Chiyoda, Tokyo
Native name	KDDI株式会社
Romanized name	Keidīdīai kabushiki gaisha
Formerly	DDI Corporation (1984–2000)
Company type	Public
Traded as	TYO: 9433; TOPIX Core 30 Component
Industry	Telecommunications
Predecessor	KDD Corporation; IDO Corporation
Founded	1953 (establishment of Kokusai Denshin Denwa or KDD as a state-owned enterprise); June 1, 1984 (as DDI)
Founder	Government of Japan (for the KDD branch); Kazuo Inamori (for the DDI branch)
Headquarters	Iidabashi, Chiyoda, Tokyo, Japan
Key people	Takashi Tanaka (businessman) (CEO); Makoto Takahashi (businessman) (president & CEO)
Products	Fixed line; mobile telephony; Internet services; digital television;
Revenue	JP¥ 5.24 trillion (2020)
Net income	JP¥ 639.77 billion (2020)
Number of employees	44,952 (2020)
Subsidiaries	List Okinawa Cellular Telephone Company (53.9%); J:COM (50%); UQ Communications (32.3%); BIGLOBE (100%); Aeon Holdings (100%); Chubu Telecommunications (80.5%); Wire and Wireless (95.2%); Telasa (50%); au Financial Holdings (100%); Supership Holdings; au Energy Holdings; KDDI Matomete Office; KDDI Digital Divergence Holdings; KDDI Engineering; KDDI Research (91.7%); KDDI Cableships & Subsea Engineering; Japan Telecommunication Engineering Service; KDDI America; KDDI China; KDDI Asia Pacific; Telehouse Holdings; Kyocera Communication System (23.4%); Mobaoku (33.4%); Kakaku.com (17.4%); Lac (32.4%);
Website	www.kddi.com/english/

KDDI Corporation (Japanese: KDDI株式会社, Hepburn: Keidīdīai kabushiki gaisha) is a Japanese telecommunications operator. It was established in 2000 through the merger of DDI Corporation (第二電電, Daini Denden), a long-distance communications company; KDD Corporation (ケイディディ), Japan's former state-monopoly international telecommunications provider; and Ido Corporation (日本移動通信, Nippon Idō Tsūshin), a mobile network operator.

In 2001, KDDI fully integrated its mobile operations by absorbing the regional companies of the DDI-Cellular Group, unifying them under Au brand. It currently stands as the second-largest mobile telecommunications provider in Japan in terms of the number of contracts, following NTT Docomo.

KDDI provides mobile cellular services primarily using Au brand, alongside its sub-brands UQ Mobile and Povo. ISP network services are provided under Au One Net brand, while Au Hikari is the name under which its Fiber to the Home (FTTH) services are marketed. Historically, the company also offered ADSL broadband (ADSL One) and IP telephony over copper (Metal Plus), but these legacy services have since been discontinued.