Deloitte

Deloitte is one of the world's largest professional services networks, known as one of the Big Four accounting firms. Deloitte LLP is the UK member firm, providing audit, consulting, financial advisory, risk advisory, tax, and legal services.

Deloitte’s history begins in Victorian London. On 23 April 1845, William Welch Deloitte opened an independent accountancy office in Basinghall Street. The growth of railways and other joint-stock enterprises created demand for accountants who could provide credible oversight of increasingly complex financial records. In 1849, Deloitte became accountant to the Great Western Railway, making him one of the first independent accountants appointed to a public company. His railway work helped establish the importance of independent examination of corporate accounts and gave the young practice a reputation for integrity and technical competence. Deloitte’s firm expanded during the second half of the nineteenth century. It moved offices within the City of London and developed relationships with railways, banks, insurers, industrial companies, newspapers, and other large enterprises. The firm also established an American presence: an office was opened in New York in 1880, followed by a Wall Street branch in 1890. These international activities laid the foundations for a network model in which nationally organized accounting practices collaborated across borders. Several other firms later became part of the Deloitte story. Charles Waldo Haskins and Elijah Watt Sells established Haskins & Sells in New York in the 1890s. George Touche established a London practice in 1898 and then helped create Touche Niven in New York in 1900. Touche’s network subsequently developed close links with Canadian, British, and Japanese organizations. In Japan, Nobuzo Tohmatsu formed Tohmatsu Aoki & Co. in 1968; that organization later became part of the international Touche Ross network. The Haskins and Deloitte traditions formally converged in 1952, when Deloitte’s British practice, then known as Deloitte, Plender, Griffiths & Co., merged with Haskins & Sells to form Deloitte Haskins & Sells. The Touche organization also grew rapidly after postwar combinations in the United States. Touche, Niven, Bailey & Smart became Touche Ross, and its leaders helped promote management consulting alongside audit and accounting. This diversification reflected a wider change in the profession: major clients increasingly sought advice on organization, systems, efficiency, technology, and finance in addition to statutory audit work. In 1989, Deloitte Haskins & Sells and Touche Ross combined in the United States and many other jurisdictions to create Deloitte & Touche. The merger was not universal. Some national practices remained outside the combination or joined other networks, demonstrating the legal and partnership complexity of global accounting organizations. Because no single entity controlled all uses of the Deloitte and Touche names, the international coordinating organization initially used the name DRT International. In 1993, it adopted Deloitte Touche Tohmatsu, later shortened in public branding to Deloitte. Deloitte continued to develop consulting as a major business. In 1995, the partners of Deloitte & Touche created Deloitte & Touche Consulting Group, which evolved into Deloitte Consulting. The firm acquired or developed capabilities in internet design, digital services, mobile applications, informatics, sustainability, blockchain, data warehousing, clinical intelligence, advertising, and customer experience. Deloitte Digital became an important vehicle for combining professional advice with software, engineering, design, marketing, and digital implementation. The collapse of Arthur Andersen after the Enron scandal reshaped the global accounting market. In 2002, Deloitte combined with Arthur Andersen’s UK practice and several Andersen practices in Spain, the Netherlands, Portugal, Belgium, Mexico, Brazil, and Canada. The move expanded Deloitte’s client relationships and professional workforce, although Deloitte France’s consulting separation created the independent consulting firm Ineum Consulting. In China, Deloitte acquired Beijing Pan-China CPA in 2005 as part of a broader investment program, strengthening the firm’s local scale. The 2000s and 2010s brought further expansion. Deloitte acquired the North American public-sector practice of BearingPoint in 2009, UK property consultancy Drivers Jonas in 2010, sustainability firms DOMANI and ClearCarbon in 2011, mobile agency Übermind in 2012, and Monitor Group in 2013. Monitor’s integration created a stronger strategy consulting platform, later associated with Monitor Deloitte. Deloitte also expanded Deloitte Digital through acquisitions such as Heat, a San Francisco advertising agency. Technology became increasingly central to Deloitte’s strategy. The organization established blockchain activities under the Rubix name, created blockchain laboratories, joined industry consortia including the Enterprise Ethereum Alliance and Hyperledger, and developed health informatics and data capabilities. In 2016, Deloitte and Apple formed an enterprise technology partnership. The same period saw the creation of larger regional structures, including Deloitte North West Europe, intended to integrate member firms and coordinate investment across markets. Deloitte’s public identity has evolved alongside its business model. The network introduced the “Always One Step Ahead” positioning platform in 2008 and later emphasized the Green Dot visual identity and a purpose of “making an impact that matters.” Social initiatives such as WorldClass, which aims to expand access to education, skills, and opportunity, and WorldClimate, which addresses emissions and climate transition, have become part of the brand’s global narrative. Deloitte has also sponsored high-profile events, including the 2012 Summer Olympics. The organization’s scale has brought continuing scrutiny. Audit litigation and regulatory actions have involved clients such as Adelphia Communications, Livent, and Malaysia’s 1MDB-linked entities. A major cyberattack disclosed in 2017 raised questions about information security and client confidentiality. These episodes illustrate the risks inherent in a professional services network whose reputation depends on independence, quality control, confidentiality, and public trust. Deloitte’s legal structure was reorganized in 2010, when the network’s member firms became associated with Deloitte Touche Tohmatsu Limited, a UK private company limited by guarantee. The member firms remained legally independent and continued to provide services under local law. In the 2020s, Deloitte continued investing in artificial intelligence, data, technology transformation, sustainability, and industry-specific advisory work. It announced the departure of its Russia and Belarus practices from the global network in 2022, selected Joseph Ucuzoglu as global CEO at the end of that year, and reported aggregate network revenue of US$70.5 billion for FY2025. As of 2026, Deloitte remains an active global professional services network with more than 470,000 people and operations across more than 150 countries and territories.

1. 2026Darren Graves becomes Deloitte UK chief executive

   Darren Graves became Deloitte UK senior partner and chief executive on 1 June 2026, while Richard Houston moved to lead Deloitte EMEA.

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2. 2025Global revenue reaches US$70.5 billion

   Deloitte reported aggregate global revenue of US$70.5 billion for the fiscal year ended 31 May 2025.

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3. 2022Russia and Belarus practices leave the network

   Deloitte announced that it would stop carrying out business in Russia and Belarus and separate those practices from the global network.

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4. 2022Joseph Ucuzoglu becomes Deloitte Global CEO

   Joseph B. Ucuzoglu succeeded Punit Renjen as Deloitte Global CEO on 31 December 2022.

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5. 2017Deloitte cyberattack disclosed

   A major cyberattack affecting Deloitte systems was disclosed, generating scrutiny over confidentiality, access controls, and information-security governance.

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6. 2016Deloitte adopts a redesigned logo

   Deloitte updated its visual identity, including a black wordmark that replaced the earlier blue treatment.

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7. 2013Monitor Group business acquired

   Deloitte acquired substantially all of Monitor Group’s business after the strategy consultancy filed for bankruptcy protection, expanding Deloitte’s strategy advisory platform.

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8. 2010Deloitte Touche Tohmatsu Limited structure takes effect

   The global organization moved from a Swiss Verein structure to Deloitte Touche Tohmatsu Limited, while member firms remained separate legal entities.

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9. 2005Beijing Pan-China CPA acquisition

   Deloitte acquired Beijing Pan-China CPA, strengthening its position and workforce in China.

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10. 2002Arthur Andersen practices join Deloitte

    Deloitte combined with Arthur Andersen’s UK practice and several Andersen practices in Europe and the Americas following Andersen’s collapse.

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11. 1995Deloitte Consulting is established

    Deloitte & Touche partners created Deloitte & Touche Consulting Group, which later became Deloitte Consulting.

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12. 1993International organization adopts Deloitte Touche Tohmatsu name

    The international coordinating organization adopted the Deloitte Touche Tohmatsu name, reflecting the Deloitte, Touche, and Tohmatsu traditions.

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13. 1989Deloitte Haskins & Sells and Touche Ross combine

    The combination created Deloitte & Touche in the United States and many other markets, forming the principal modern foundation of the global network.

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14. 1952Deloitte merges with Haskins & Sells

    Deloitte’s British practice merged with Haskins & Sells to form Deloitte Haskins & Sells.

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15. 1890Wall Street branch opens

    A Wall Street branch became Deloitte’s first overseas venture described as a formal international branch, followed by expansion to other American cities and Buenos Aires.

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16. 1880First New York office

    Deloitte opened an office in New York, beginning the firm’s long-term expansion beyond the United Kingdom.

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17. 1849Deloitte becomes accountant to Great Western Railway

    Deloitte was appointed accountant to the Great Western Railway, an early public company, helping establish independent corporate auditing as a core professional practice.

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18. 1845William Welch Deloitte opens a London accountancy practice

    William Welch Deloitte opened an independent accountancy office in London on 23 April 1845, establishing the historical foundation of the Deloitte organization.

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A prestigious, multidisciplinary professional services network positioned around trust, technical quality, global reach, industry expertise, and the integration of business advice with technology and transformation capabilities.

• Audit & AssuranceAudit and accounting1845

  Deloitte’s audit and assurance practices examine financial statements, internal controls, risk processes, and selected nonfinancial information. Services are delivered by local member firms under applicable national regulation and professional standards. In addition to statutory audit, the offering can include accounting and reporting advisory, controls assurance, sustainability assurance, and support for complex transactions. Audit remains the service most closely associated with Deloitte’s historical identity and its role in supporting confidence in capital markets.

• ConsultingManagement and technology consulting1995

  Deloitte Consulting advises organizations on strategy execution, operating models, technology transformation, enterprise systems, supply chains, customer experience, workforce, finance, and large-scale change programs. The practice combines business consulting with engineering, implementation, analytics, cloud, cybersecurity, and artificial intelligence capabilities. Its work ranges from operating-model redesign to the deployment of systems and digital products intended to produce measurable changes in performance.

• Tax & LegalTax and legal services

  Deloitte’s Tax & Legal practices help companies and individuals manage tax compliance, reporting, controversy, transfer pricing, indirect taxes, international structuring, employment taxes, and transaction-related tax issues. In jurisdictions where permitted, Deloitte member firms also provide legal services, often integrated with tax, technology, regulatory, and corporate-transactions advice. The offering increasingly includes digitally enabled compliance and systems designed to manage complex, changing regulatory requirements.

• Strategy, Risk & Transactions AdvisoryStrategy, risk, and transactions2013

  This portfolio addresses corporate strategy, economic and geopolitical risk, enterprise risk management, regulatory matters, mergers and acquisitions, restructuring, valuation, forensic investigations, and transaction execution. Monitor Deloitte contributes strategy consulting capabilities, while other practices support due diligence, integration, divestiture, restructuring, disputes, and complex capital or infrastructure projects. The combination allows Deloitte to advise clients from strategic planning through transaction implementation and post-deal transformation.

• Deloitte DigitalDigital transformation and marketing2012

  Deloitte Digital combines consulting, design, engineering, marketing, customer experience, data, and technology services. It works with organizations on digital products, commerce, customer journeys, brand experiences, mobile applications, marketing technology, and platform transformation. The unit grew through internal development and acquisitions in digital design, advertising, and mobile services, helping Deloitte compete with both traditional consultancies and global digital agencies.

• Cyber, Data and Artificial IntelligenceTechnology and risk services

  Deloitte provides cybersecurity, privacy, digital identity, data engineering, analytics, artificial intelligence, cloud, and technology-risk services. These offerings support security assessments, incident preparedness, governance, regulatory compliance, data platforms, automation, and the practical deployment of generative AI. They reflect the network’s strategic shift toward technology-enabled services and its effort to integrate advisory expertise with implementation and engineering capabilities.

• 2016Green Dot brand campaign

  Global

  Deloitte used the Green Dot visual identity and related communications to express a consistent global brand while emphasizing energy, optimism, progress, and the organization’s forward-looking positioning.

  Outcome. The Green Dot became one of Deloitte’s most recognizable brand assets and remained central to its visual identity.

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• 2015WorldClass

  Global

  Deloitte launched WorldClass as a global social-impact initiative focused on helping people gain skills, education, and access to economic opportunity.

  Outcome. The program became a prominent part of Deloitte’s purpose-led brand platform and global community-investment narrative.

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• 2015WorldClimate

  Global

  WorldClimate brought together Deloitte’s climate commitments, emissions-reduction objectives, internal operations, and climate-related client work.

  Outcome. The initiative became a core element of Deloitte’s environmental positioning and public reporting.

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• 2012London 2012 Olympic sponsorship

  United Kingdom · International

  Deloitte sponsored activities connected with the 2012 Summer Olympics, using the event to associate the brand with large-scale transformation, performance, public-private collaboration, and international reach.

  Outcome. The sponsorship increased the brand’s visibility beyond the professional services sector and connected Deloitte with a globally watched event.

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• 2012Deloitte Digital launch and expansion

  Global

  Deloitte expanded its digital brand proposition through Deloitte Digital, bringing together technology, customer, design, marketing, and transformation capabilities.

  Outcome. Deloitte Digital became a major growth platform and was subsequently enlarged through acquisitions in advertising, mobile, and digital experience.

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• 2008Always One Step Ahead

  Global

  Deloitte introduced “Always One Step Ahead” as a global brand-positioning platform supporting its broader vision of being a standard of excellence. The phrase was used as a strategic positioning concept rather than a conventional consumer advertising tagline.

  Outcome. The platform helped unify Deloitte’s international brand narrative around anticipation, expertise, and forward-looking advice.

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• 2026Change Deloitte UK leadershipOther

  Deloitte UK reorganized senior leadership as Richard Houston moved to lead the newly formed Deloitte EMEA organization.

  What changed. Darren Graves became Deloitte UK senior partner and chief executive on 1 June 2026.

  Aftermath. The change placed a tax and transactions specialist at the head of the UK member firm while aligning UK leadership with the new EMEA structure.

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• 2022Separate Russia and Belarus practices from the global networkStrategy

  Russia’s invasion of Ukraine created legal, ethical, reputational, and operational pressures for multinational professional services networks.

  What changed. Deloitte announced that it would no longer conduct business in Russia or Belarus and would separate the practices in those countries from the global network.

  Aftermath. The decision aligned Deloitte with a wider wave of corporate withdrawals and reorganizations following the invasion.

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• 2022Appoint Joseph Ucuzoglu as Deloitte Global CEOOther

  Deloitte’s global CEO succession process occurs through a partner selection and ratification process across member firms.

  What changed. Deloitte selected Joseph B. Ucuzoglu to succeed Punit Renjen, with Ucuzoglu assuming the global CEO role at the end of December 2022.

  Aftermath. The organization continued emphasizing technology-enabled transformation, artificial intelligence, social impact, and climate action under Ucuzoglu’s leadership.

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• 2017Expand blockchain and distributed-ledger capabilitiesStrategy

  Clients in financial services, government, and other industries were exploring blockchain, tokenization, and distributed-ledger applications.

  What changed. Deloitte expanded blockchain consulting through Rubix, established laboratories, and joined industry initiatives including the Enterprise Ethereum Alliance and Hyperledger.

  Aftermath. Blockchain became part of Deloitte’s broader emerging-technology advisory portfolio, alongside cloud, data, cybersecurity, and artificial intelligence.

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• 2013Acquire Monitor Group businessM&A

  Deloitte sought to strengthen its high-end strategy consulting capabilities and compete more directly with strategy specialists and diversified consulting firms.

  What changed. Deloitte acquired substantially all of Monitor Group’s business after Monitor filed for bankruptcy protection.

  Aftermath. The acquisition expanded Deloitte’s strategy offering and led to the development of Monitor Deloitte as a prominent strategy brand within the network.

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• 2002Integrate Arthur Andersen practicesM&A

  Arthur Andersen’s collapse after the Enron scandal created an opportunity for surviving professional services networks to recruit people and absorb client-service practices.

  What changed. Deloitte agreed to combine with Arthur Andersen’s UK practice and several Andersen practices in Europe and the Americas.

  Aftermath. Deloitte expanded its international scale and market position, while some consulting operations were separated in individual jurisdictions.

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• 1995Create Deloitte ConsultingStrategy

  Clients were seeking integrated advice on operations, organization, information systems, and business transformation in addition to audit and accounting.

  What changed. Deloitte & Touche partners established Deloitte & Touche Consulting Group, later known as Deloitte Consulting.

  Aftermath. Consulting became a major pillar of Deloitte’s multidisciplinary model and later expanded into technology, implementation, digital, and artificial intelligence services.

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• 1989Combine Deloitte Haskins & Sells and Touche RossM&A

  The accounting profession was consolidating internationally, and large clients increasingly expected firms to provide audit, consulting, and cross-border services through coordinated networks.

  What changed. Deloitte Haskins & Sells and Touche Ross combined in the United States and many other jurisdictions to form Deloitte & Touche.

  Aftermath. The transaction created the principal modern platform for the Deloitte global network, although some national member firms did not participate and joined other organizations.

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• 20211MDB-related audit settlement in MalaysiaControversy

  Deloitte’s Malaysian affiliate agreed to pay the Malaysian government US$80 million to resolve claims connected with audits of accounts associated with 1MDB and SRC International. The settlement occurred against the background of the broader 1MDB financial scandal and regulatory scrutiny of professional advisers.

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• 2017Deloitte cybersecurity breachControversy

  Deloitte disclosed a cyberattack involving access to systems containing confidential client and employee information. Public reporting described compromised credentials and emails, while Deloitte stated that the number of affected clients was limited and that investigations found no disruption to client businesses. The incident generated criticism of access controls, cloud-security practices, and incident disclosure.

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• 2017Livent audit litigationControversy

  Deloitte faced litigation arising from its former audit relationship with Canadian entertainment company Livent. The case concerned allegations about whether audit work should have detected fraudulent activity in the company’s financial reporting.

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• 2005Adelphia audit regulatory actionControversy

  The U.S. Securities and Exchange Commission announced a settlement with Deloitte & Touche concerning charges related to the audit of Adelphia Communications’ 2000 financial statements. The matter contributed to continuing scrutiny of auditor responsibilities and audit quality.

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• 2026Deloitte UK appoints Darren Graves as chief executive

  Darren Graves became Deloitte UK senior partner and chief executive on 1 June 2026, succeeding Richard Houston. Houston moved to lead the newly formed Deloitte EMEA organization.

  Leadership change
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• 2025Deloitte reports US$70.5 billion in FY2025 global revenue

  Deloitte reported aggregate network revenue of US$70.5 billion for the fiscal year ended 31 May 2025, with more than 470,000 people worldwide. The announcement emphasized demand for artificial intelligence, advanced technology, and transformation services.

  OtherProduct generation
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• 2025Deloitte UK reports softer FY2025 revenue and continued technology investment

  Deloitte UK reported revenue of £5.68 billion for the year ended 31 May 2025, down 1% year over year, while continuing investment in technology, artificial intelligence, learning, and reward programs.

  PricingOther
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• 2024Jason Salzetti named chair and CEO of Deloitte Consulting LLP

  Deloitte US announced that Jason Salzetti would become chair and CEO of Deloitte Consulting LLP effective January 27, 2025, succeeding Dan Helfrich.

  Leadership change
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• 2022Deloitte exits Russia and Belarus operations

  Following Russia’s invasion of Ukraine, Deloitte announced that it would cease business activity in Russia and Belarus and separate the practices in those countries from the global network.

  M&ARegulation
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• 2022Deloitte Consulting completes acquisition of BIAS Corporation

  Deloitte Consulting completed the acquisition of substantially all assets of BIAS Corporation, adding Oracle Cloud Infrastructure and Oracle Cloud Applications specialists in the United States and India to its cloud engineering capabilities.

  M&A
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• 2022Deloitte developed statewide Georgia Access public-awareness campaigns

  Deloitte supported Georgia’s effort to establish and promote Georgia Access, using audience research, behavioral insights, omnichannel media, and creative communications to improve awareness of health-insurance enrollment opportunities.

  Campaign
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• 2022Deloitte US presented a refreshed brand campaign around progress and innovation

  Deloitte’s US brand team worked with PartnersCreative on a nationwide campaign using concise verbal narratives and 3D animation to express themes including innovation, trust, resilience, and shaping the future.

  Campaign
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• 2016Deloitte and Apple announce enterprise technology partnership

  Deloitte and Apple announced a partnership under which Deloitte consultants would advise business clients on the use of Apple hardware, software, and services, including an enterprise-focused offering known as Enterprise Next.

  CampaignProduct launch
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• 2016Deloitte Digital acquires advertising agency Heat

  Deloitte acquired substantially all assets of San Francisco-based Heat and placed the agency within Deloitte Digital as a full-service creative operation.

  M&A
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• 2016Deloitte Digital introduces Digital Marketing Hub

  Deloitte Digital introduced a Salesforce Marketing Cloud-based offering intended to connect marketing strategy, content, creative, execution, analytics, and data management.

  Product launch
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• 2013Deloitte acquires Monitor Group

  Deloitte acquired substantially all of the business of Monitor Group, a strategy consulting firm founded by Michael Porter, after Monitor filed for bankruptcy protection. The transaction strengthened Deloitte’s strategy consulting capabilities.

  M&A
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• 2002Deloitte absorbs substantial Arthur Andersen practices

  Deloitte agreed to combine with Arthur Andersen’s UK practice and several Andersen practices in Europe and the Americas after the collapse of Arthur Andersen, significantly expanding Deloitte’s international footprint.

  M&A
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1. Deloitte: Our heritage
2. Happy Birthday(s), Deloitte: The Significance of 1845
3. The Ties That Bind: Deloitte history
4. Deloitte reports FY2025 revenue
5. Deloitte Global leadership message and board information
6. Deloitte Global CEO Joseph B. Ucuzoglu profile
7. Deloitte UK announces Darren Graves as senior partner and chief executive
8. Deloitte UK publishes 2025 financial results
9. Deloitte
10. Deloitte & Touche v Livent Inc.
11. SEC Charges Deloitte & Touche for Adelphia Audit
12. Joseph Ucuzoglu becomes Deloitte Global CEO
13. Deloitte agreed to a settlement in a US government investigation of DEI-related hiring practices
14. Jason Salzetti named chair and CEO of Deloitte Consulting LLP
15. Deloitte Consulting completes acquisition of BIAS Corporation
16. Deloitte developed statewide Georgia Access public-awareness campaigns
17. Deloitte US presented a refreshed brand campaign around progress and innovation
18. Deloitte Digital acquires advertising agency Heat
19. Deloitte Digital introduces Digital Marketing Hub