From ACT Wiki
Deloitte is the short name for Deloitte Touche Tohmatsu Ltd (DTTL), one of the 'Big 4' largest worldwide professional services organisations and auditors.
'Deloitte' is the brand under which member firms collaborate to provide services to clients. These firms are members of Deloitte Touche Tohmatsu Limited, a UK private company limited by guarantee.
DTTL (also known as 'Deloitte Global') does not provide services to clients.