Deloitte

Deloitte (formerly Deloitte Touche Tohmatsu Limited) is one of the "big four" accounting organizations, as well as the largest network of professional services by revenue and by total number of professionals. In 2018, the company reported $43.2 billion USD total revenue. The company offers consulting, tax, enterprise risk, financial advisory, and other services using a network of over 286,200 professionals around the world. The business also has the largest number of clients of all the FTSE 250 companies in the UK. Its headquarters are located in London, but it operates globally.

Deloitte was founded by William Welch Deloitte, who opened a London office in 1845. Deloitte was the first person to be appointed as an independent auditor for a public company - that company was the Great Western Railway. He would go on to open another office in 1880 in New York, and in another in 1890 in Wall Street.

Since its launch, the company has undergone numerous mergers and acquisitions, merging with Touche Ross in the USA in 1989 to form Deloitte Touche, and was later renamed Deloitte Touche Tohmatsu in 1993 (referring to Tohmatsu Aoki & Co which became part of the Touche Ross network in 1975).