Until 2020, KPMG, was the only Big 4 firm not registered as a UK private company, but rather the co-ordinating entity was a Swiss association (verein). However, KPMG International changed its legal structure from a verein to a co-operative under Swiss law in 2003, then to a UK limited company in 2020. For Deloitte, PricewaterhouseCoopers and Ernst & Young, the co-ordinating entity is a UK limited company. Those entities "do not" themselves perform external professional services, nor do they own or control the member firms. Nevertheless, these networks colloquially are referred to as "firms" for the sake of simplicity and to reduce confusion with lay-people. These accounting and professional services networks are similar in nature to how law firm networks in the legal profession work.