NTT DATA’s history goes back to 1967, when the DATA Communications Bureau was established within the Japan Telegraph and Telephone Public Corporation (now NTT). Its mainframe ultra-large-scale computer DIPS-11 Model 45 was developed in 1981. In 1988 NTT DATA Communications Systems Corporation was spun off into a separate company from NTT. Authorized as a Systems Integrator in 1990, in 1992 the company had its headquarters relocated to Toyosu, Koto-ku, Tokyo. The company received the Deming Application Prize for 1993, and was listed on the Second Section of the Tokyo Stock Exchange in 1995. In 1996, the company changed its English name to NTT DATA Corporation, and it was also listed on the First Section of the Tokyo Stock Exchange. The company obtained ISO 9001 certification in 1998, and ISO 14001 certification in 1999.
In 2002 it was the first Japanese company to obtain BS 7799 certification, an international information security standard. In 2007, the company had consolidated net sales of ¥1 trillion, and in 2008 the company acquired German-based Cirquent, Inc. A new organizational structure of the "Company System" was introduced in 2009. Also that year, the company acquired Extend Technologies Pty Ltd in Australia, as part of a strategy to expand the global footprint of specialised SAP consulting businesses.
NTT DATA and Boston-based IT Service company Keane agreed to a merger on 29 October 2010. The acquisition is worth over US$1.23 billion. After the acquisition of Keane Inc., NTT DATA became the 8th largest software company in the world, with the annual revenue of $14 billion. Acquiring Keane Inc. in 2010 increased the Group’s total work force to 50,000. That year the company also acquired FirstApex, increasing the business footprint in insurance domain. In 2010, NTT DATA acquired Intelligroup Inc., an US-based IT consulting and service providing company. After taking over Intelligroup, NTT became the ninth largest software company in the world, worth over $11 billion. India-based Intelligroup, Inc is headquartered at iLabs, Madhapur, Hyderabad.
In 2011, the company acquired Italy-based Value Team S.p.A. and launched Global One Teams. In 2012 the company acquired London-based Design and Technology Consultancy, RMA Consulting, who specialize in software design and delivery across multiple channels.
In 2013, the company acquired Madrid-based Everis, a company that provided IT services including consulting, system integration and outsourcing. Also in 2013, NTT DATA, the IT services provider with its U.S. headquarters in Plano, acquired Optimal Solutions Integration, a provider of SAP services headquartered in Irving, Texas. In 2015, the company acquired Carlisle & Gallagher, Inc., a Charlotte-based consulting firm. Also that year, the company acquired iPay88 - Online Payment Gateway for Asia Countries, Malaysia which specialize in online payment services and payment solutions for merchants with multiple financial institutions as business partners in Malaysia. In 2016, the company acquired the Dell IT Services unit (mainly the former Perot Systems) of Dell Inc for $3 billion. Also in 2016, the company acquired Nefos, a Salesforce consulting partner in Germany, Austria and Switzerland.