The 'Big Four' refers to the four largest firms in the world of accountancy and auditing, which include Deloitte, Ernst & Young, KPMG, and PricewaterhouseCoopers, as well as the major commercial banks in the UK such as Barclays, Lloyds, HSBC, and Royal Bank of Scotland.
KPMG is one of the Big Four international professional services networks, providing audit, tax, and advisory services across over 150 countries.
