The Big Four are the four largest professional services networks in the world: Deloitte, EY, KPMG, and PwC. They are the four largest global accounting networks as measured by revenue. The four are often grouped because they are comparable in size relative to the rest of the market, both in terms of revenue and workforce; they are considered equal in their ability to provide a wide scope of professional services to their clients; and, among those looking to start a career in professional services, particularly accounting, they are considered equally attractive networks to work in, because of the frequency with which these firms engage with Fortune 500 companies.
Ernst & Young Global Limited, trade name EY, is a multinational professional services partnership. EY is one of the largest professional services networks in the world. Along with Deloitte, KPMG and PwC, it is considered one of the Big Four accounting firms. It primarily provides assurance, tax, information technology services, consulting, and advisory services to its clients.
KPMG International Limited is a multinational professional services network, and one of the Big Four accounting organizations, along with Ernst & Young (EY), Deloitte, and PwC. The name "KPMG" stands for "Klynveld Peat Marwick Goerdeler". The initialism was chosen when KMG merged with Peat Marwick in 1987.
H&R Block, Inc., or H&R Block, is an American tax preparation company operating in Canada, the United States, and Australia. The company was founded in 1955 by brothers Henry W. Bloch and Richard Bloch.
Deloitte Touche Tohmatsu Limited, commonly referred to as Deloitte, is a British multinational professional services network. Deloitte is the largest professional services network by revenue and number of employees in the world and is considered one of the Big Four accounting firms, along with EY, KPMG, and PwC.
Grant Thornton LLP is the American member firm of Grant Thornton International, the seventh largest accounting network in the world by combined fee income. Grant Thornton LLP is the seventh largest U.S. accounting and advisory organization. The firm operates 59 offices across the US with approximately 8,500 employees, 550 partners, and produces annual revenue in excess of US$1.9 billion.
The Interpublic Group of Companies, Inc. (IPG) is an American publicly traded advertising company. The company consists of five major networks: FCB, IPG Mediabrands, McCann Worldgroup, MullenLowe Group and Marketing Specialists, as well as several independent specialty agencies in the areas of public relations, sports marketing, talent representation and healthcare. It is one of the "Big Four" agency companies, alongside WPP, Publicis and Omnicom. Phillippe Krakowsky became the company's CEO on January 1, 2021.
RSM US LLP is an audit, tax, and consulting firm focused on the middle market in the United States and Canada and is a member of the global accounting network RSM International. RSM US has been ranked as the 7th most prestigious accounting firm in the US as voted on by accounting professionals. It employs more than 16,800 professionals across 81 cities nationwide and in Canada. RSM US also maintains offices in India and El Salvador. In 2024, RSM fired their Chief Diversity Officer, Tracey Walker, who was the only woman of color in leadership, and drastically cut funding to their diversity and inclusion programs.
RSM Robson Rhodes LLP was a partnership of chartered accountants in the United Kingdom and Ireland. It was the UK member firm of RSM Global, the 6th largest network of professional accountancy firms in the world. With offices throughout the UK and Ireland, the firm offered auditing, consultancy and tax services to a wide variety of organisations in the private and public sectors.
RSM Tenon was a professional services firm based in the United Kingdom, which was listed on the FTSE SmallCap Index and part of RSM Global. The company was formed from the merger of the Tenon Group with RSM Bentley Jennison in December 2009.
Grant Thornton is a multinational professional services company based in London, England. It is the world's seventh-largest by revenue and sixth-largest by number of employees professional services network of independent accounting and consulting member firms which provide assurance, tax and advisory services to privately held businesses, public interest entities, and public sector entities. Grant Thornton International Ltd. is a not-for-profit, non-practising, international umbrella membership entity organised as a private company limited by guarantee, and has no share capital.
RSM UK is a provider of audit, tax, and consulting services to middle-market businesses. It is the seventh-largest business advisory firm in the United Kingdom and the sixth-largest globally.
HLB International is a global network of independent advisory and accounting firms, comprising member firms in 157 countries. HLB International member firms offer audit, accounting, tax and business advisory services.
An accounting network or accounting association is a professional services network whose principal purpose is to provide members resources to assist the clients around the world and hence reduce the uncertainty by bringing together a greater number of resources to work on a problem. The networks and associations operate independently of the independent members. The largest accounting networks are known as the Big Four.
The Forum of Firms is an association of international networks of accounting firms that perform transnational audits.
Baker Tilly International is a consulting and public accounting firm. It is currently the 9th largest accounting network in the world by revenue with 43,000 people in 700 offices across 141 territories with combined global revenues of $5.2bn. Baker Tilly operates geographically through four regions: Asia Pacific; Europe, Middle East and Africa; Latin America; and North America. Each region has a chair, appointed by the International Board, who leads an advisory council elected by members in that region.
John B. Veihmeyer was global chairman of KPMG from April 2014 till September 2017. He previously served as chairman and chief executive officer of KPMG's U.S. firm for a five-year term from 10 June 2010 until 9 June 2015. William B Thomas, 49, has been elected Chairman of KPMG International. He will lead the KPMG global network of professional services firms for a 4-year term, effective 1 October 2017, succeeding John B Veihmeyer, 61, who is completing his term as Chairman and retiring from the firm, at the end of September 2017.
BDO is an international network of public accounting, tax, consulting and business advisory firms that provide professional services under the name BDO. It is the fifth-largest accounting network in the world. Global fee income of the member firms in the network for the year ended 30 September 2021, including the members of their exclusive alliances, totaled US$12.8 billion. Each BDO member firm is an independent legal entity in its own country. The network, founded in 1963 as Binder Seidman International Group by firms from Canada, Germany, the Netherlands, the UK and the US, is coordinated by BDO Global Coordination B.V., with an office in Zaventem, Belgium. In 1973, the organisation adopted the name BDO, made up from the initials of the three founding firms: Binder (UK), Dijker (Netherlands) and Otte (Germany).
Dinesh Kanabar is an entrepreneur and international tax expert. He is founder and CEO of Dhruva Advisors, one of the largest tax and regulatory boutiques in India that has been consistently rated as India Tax Firm of the year over the years. Prior to founding Dhruva, Dinesh held various positions, including Deputy CEO of KPMG in India and Deputy CEO of RSM. Dinesh works closely with some of the largest multi-national corporations and Indian business houses advising on business, tax and regulatory matters. He has worked on some of the largest mergers and acquisitions, corporate restructuring and tax litigation engagements in the country. He also works very closely with the Government of India on Tax Policy matters. Dinesh has been recognized as Asia Tax Practice Leader of the Year-2020 by International Tax Review, and he regularly pens articles on a variety of subjects ranging from tax to leadership.
US$9.4 billion (2023) [1] 
