A cash machine, or automated teller machine (ATM), allows users to make cash withdrawals, check their account balance, order cheque books, change their PIN (personal identification number), request statements, pay bills, make deposits, transfer money and order mini statements 'at the touch of a button'. Many cash machines now also provide a facility for users to top-up mobile phones.

Withdrawals from cash machines are the most popular way to acquire cash in the UK and around two-thirds of adults are regular users. Many of today's machines are available 24 hours a day, 365 days a year and, with the so-called cashless society still a long way off, cash machines are expected to remain an integral part of everyday life for many years to come.

Banks and building societies have arrangements in place to allow their customers access to their accounts via cash machines owned by other institutions.

There are two types of cash machine provider in the UK: banks and building societies and non-financial organisations more commonly known as independent ATM deployers (IADs).