What's the difference between the Big Four accounting firms?

Is it just six of one and half-a-dozen of the other?
Where to work

The Big Four accounting firms, or professional services networks as they're sometimes also known, are multinational conglomerates that have grown to become some of the largest organisations in the world.

They're traditionally known for their audit work – an inspection of a company's accounts that is legally required once a year – which continues to be their main source of revenue. Between them, the Big Four reportedly audit 99 per cent of FTSE 100 companies.

They also provide other services including tax work, consulting services and corporate finance advice.


Company type: Privately held, limited by guarantee

Global headquarters: New York, USA

Employees: 225,400

Revenue: $35.2 billion

Best known for: Audit, Tax

The firm is often regarded as having an outgoing and ambitious culture, and is known for hiring sharp, analytical graduates.

Deloitte has a history of winning impressive clients including consumer products company Procter & Gamble, which it's audited for over 100 years.

The firm works with 82 per cent of the 2013 Fortune Global 500. In the most recent financial year, 27 per cent ($9.5 billion) of the firm’s income came from financial services clients, while a further 12.5 per cent ($6.6 billion) derived from the consumer sector.

Deloitte's main source of revenue comes from its  operations in the Americas (52 per cent), with the Europe Middle East and Africa (EMEA) region currently its second biggest source of revenue.


Company type: Limited Liability Partnership

Global headquarters: London, UK

Employees: 208,109

Revenue: $35.4 billion

Best known for: Assurance, Tax

PwC is often viewed as the most prestigious of all the Big Four to work for and employees there are very conscious of that fact. The company is also known to invest a lot in training and development for its employees.

In 2015, PwC regained its crown as the top firm in terms of global revenue, narrowly outperforming rival Deloitte. The UK has been a particularly successful market for the firm is recent years – it achieved a 10 per cent growth in revenue in 2014/15 as it brought in £3.08 billion. 


Company type: Swiss Cooperative

Global headquarters: Amstelveen, Netherlands

Employees: 173,965

Revenue: $24.44 billion

Best known for: Consulting, Tax

The name KPMG is made up of the initials of the firm's founding members and, although it has only existed in its current form since the late 1980s, the Dutch-born firm can trace its history back 300 years.

It's known for its smart graduates, collaborative atmosphere and allegedly rather eccentric culture.

KPMG is probably the most Europe-focused of all the Big Four. In 2014/15, its UK revenues jumped by 2.6 per cent to £1.96 billion. In comparison to the other Big Four firms, KPMG is known for its consultancy/advisory work, which contributed £839 million, or 43 per cent of total sales, in 2014/15.


Company type: Limited Liability Partnership

Global headquarters: London, UK

Employees: 212,000

Revenue: $28.7 billion

Best known for: Audit & Assurance, Consulting

EY is one of the smaller of the Big Four firms in the UK by number of employees, and is reputed to have a slightly more relaxed and friendly working atmosphere than the others. It's also consistently recognised for its work promoting LGBT rights in the workplace.

It's also ranks behind Deloitte and PwC in terms of revenue, and out of the Big Four it audits the least number of FTSE 100 companies.

However, in 2014/15 EY's UK business narrowly overtook that of its closest rival KPMG, with the firm reporting UK fee income of just over £2 billion. 

Much of this success has been attributed to the growth of EY’s audit business after a restructuring saw UK audit revenues increase by 8 per cent.

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