Early history In 1845,
William Welch Deloitte opened an office in
Basinghall Street in London, England. Deloitte was the first person to be appointed an independent auditor of a public company, namely the
Great Western Railway. He went on to open an office in New York in 1880. when it moved to No. 54 London Wall Buildings. In 1890, Deloitte opened a branch office on
Wall Street headed by Edward Adams and P.D. Griffiths as branch managers. This was Deloitte's first overseas venture. Other branches were soon opened in
Chicago and
Buenos Aires. In 1898 P.D. Griffiths returned from New York and became a partner in the London office. In 1896,
Charles Waldo Haskins and
Elijah Watt Sells formed Haskins & Sells in New York. In 1898,
George Touche established an office in London and then, in 1900, joined John Ballantine Niven in establishing the firm of Touche Niven in the Johnston Building at 30
Broad Street in New York. In 1989, Deloitte Haskins & Sells merged with Touche Ross in the US to form Deloitte & Touche. The merged firm was led jointly by
J. Michael Cook and Edward A. Kangas. Led by the UK partnership, a smaller number of Deloitte Haskins & Sells member firms rejected the merger with Touche Ross and shortly thereafter merged with Coopers & Lybrand to form Coopers & Lybrand Deloitte (later to merge with Price Waterhouse to become
PwC). Some member firms of Touche Ross also rejected the merger with Deloitte Haskins & Sells and merged with other firms.
Recent history At the time of the US-led mergers to form Deloitte & Touche, the name of the firm was a problem, because there was no worldwide exclusive access to the names "Deloitte" or "Touche Ross" – key member firms such as Deloitte in the UK and Touche Ross in Australia had not joined the merger. The name DRT International was therefore chosen, referring to Deloitte, Ross and Tohmatsu. In 1993, the international firm was renamed Deloitte Touche Tohmatsu. In 2000, Deloitte acquired Eclipse to add internet design to its consulting capabilities. Eclipse was later separated into Deloitte Online and Deloitte Digital. In 2002,
Arthur Andersen's UK practice, the firm's largest practice outside the US, agreed to merge with Deloitte's UK practice. Andersen's practices in Spain, the Netherlands, Portugal, Belgium, Mexico, Brazil and Canada also agreed to merge with Deloitte. The spinoff of Deloitte France's consulting division led to the creation of
Ineum Consulting. In 2005, Deloitte acquired Beijing Pan-China CPA to become the largest accountancy firm in China. Just prior to this acquisition Deloitte China had about 3,200 employees. This acquisition was part of a five-year plan to invest $150 million in China. Deloitte has had a presence in China since 1917. In 2007, Deloitte began hiring former employees of the
Central Intelligence Agency (CIA) for their
competitive intelligence unit known as Deloitte Intelligence. In 2009, Deloitte purchased the North American public service practice of
BearingPoint (formerly
KPMG Consulting) for $350 million after it filed for bankruptcy protection. Deloitte LLP took over the UK property consultants
Drivers Jonas in January 2010. As of 2013, this business unit was known as Deloitte Real Estate. In 2011, Deloitte acquired DOMANI Sustainability Consulting and ClearCarbon Consulting in order to expand its sustainability service offerings. In January 2012, Deloitte announced the acquisition of Übermind, a mobile advertising agency. The acquisition marked Deloitte's first entrance into the mobile application field. In November 2012, Deloitte acquired Recombinant Data Corporation, a company specializing in
data warehousing and clinical intelligence software, and launched Recombinant by Deloitte. In February 2013 Recombinant by Deloitte merged with an internal
informatics unit (Deloitte Health Informatics) and launched ConvergeHEALTH by Deloitte. On 11 January 2013, Deloitte purchased substantially all of the business of
Monitor Group, the strategy consulting firm founded by
Harvard Business School professor
Michael Porter, after Monitor filed for bankruptcy protection. In 2014, the company introduced Rubix, a
blockchain consultancy providing advisory services for clients in different business sectors, including government. In 2016 the company created its first blockchain lab in Dublin. A second hub was launched in
New York in January 2017. In 2016, Deloitte Canada set up a Bitcoin automatic teller machine and equipped a restaurant in its office complex to accept Bitcoin as payment. Deloitte CIS partnered with Waves Platform to offer services related to
initial coin offerings. Deloitte became a member of the
Ethereum Enterprise Alliance and the Hyperledger Project sponsored by the
Linux Foundation in May 2017. In 2016, Deloitte acquired the advertising agency Heat of San Francisco, best known for its work for
Madden NFL from
EA Sports and the
Hotwire travel website. Heat was the 11th digital marketing agency purchased by Deloitte Digital since its founding in 2012. As of 2016, Deloitte Digital had 7,000 employees. It billed $2.1 billion in 2015, making it one of world's largest digital agencies. In September 2016,
Apple Inc. announced a partnership with Deloitte aimed at boosting sales of its phones and other mobile devices to businesses. As part of the partnership, the two companies will launch a service called Enterprise Next, in which more than 5,000 Deloitte consultants will advise clients on how to make better use of Apple products and services. In October 2016, Deloitte announced that they were creating Deloitte North West Europe. The Belgian, Danish, Dutch, Finnish, Icelandic, Norwegian, and Swedish member firms will combine with the UK and Swiss member firms to create Deloitte North West Europe. Deloitte, over the next three years, would invest €200m to enhance its services to its global, national and private market clients and to create development opportunities. The firm came into effect on 1 June 2017 and it is estimated to have 28,000 partners and people generating over €5bn in annual revenue. Deloitte North West Europe accounts for approximately 20% of all revenue within their Global Network. In March 2022, Deloitte announced that, as a result of the
Russo-Ukrainian War, the firm would no longer carry out business in
Russia or
Belarus, and would separate its practices within these countries from its global network of firms. In March 2022, Deloitte acquired Etain, a data and digital transformation specialist company, based in
Northern Ireland. The
Wall Street Journal reported in June 2022 that the firm might choose to divide itself into two new companies, one accounting firm and one advisory firm. The
Wall Street Journal reported this potential change several weeks after reporting that
Ernst & Young was considering a similar split. In November 2023, Deloitte entered into a supply contract with Henchmann, a provider of contract drafting and negotiation software that scans and extracts key data points from legal documents. In 2024, Deloitte,
Nvidia,
Microsoft and
Amazon Web Services provided a combined $40 million in funding to multiple cancer institutes to support the establishment of the Cancer AI Alliance. In May 2025, the company informed its UK consulting division it planned to reduce pay rises and cut bonuses by 20 per cent following poor financial performance. In March 2025, Deloitte announced the appointment of Darren Graves as its UK chief executive, replacing Richard Houston. ==Name and branding==