Deloitte

Deloitte traces back to 1845, when accountant William Welch Deloitte opened an office in London. The network grew through mergers, including Haskins & Sells in 1952 and Touche Ross in the US in 1989, and has been called Deloitte Touche Tohmatsu since 1993. Its coordinating entity, Deloitte Touche Tohmatsu Limited (DTTL), is a UK private company limited by guarantee based in London. DTTL does not provide services to clients: the work is done by legally separate member firms.

Deloitte offers audit and assurance, consulting, tax and legal, and advisory services. Consulting is split into Strategy, Risk & Transactions and Technology & Transformation, and the global site lists Engineering, AI & Data, Enterprise Technology & Performance, Cyber and Artificial Intelligence among its offerings. It names alliance partners including AWS, Google, NVIDIA, Oracle, Salesforce, SAP, ServiceNow and Workday.

For the fiscal year ended 31 May 2025 Deloitte reported aggregate revenue of US$70.5 billion, and its Global Impact Report gives 473,050 people. It operates in more than 150 countries and territories. Deloitte publishes no single list of technology centres on its global pages, and its US firm refers to a US Delivery Center.