An automatic teller machine or automated teller machine (ATM) is an electronic device that allows a bank's customers to make cash withdrawals and check their account balances without the need for a human teller. Many ATMs also allow people to deposit cash or cheques, transfer money sport ween their bank accounts, top up their mobile phones' pre-paid accounts or even buy postage stamps.
In most modern ATMs, the customer identifies him or herself by inserting a plastic card with a magnetic stripe that contains his or her account number. The customer then verifies his or her identity by entering a passcode (PIN) of four or more digits. If the number is entered incorrectly several times in a row (usually three), most ATMs will retain the card as a security precaution to prevent an unauthorised user from discovering the PIN by guesswork (these cards are sometimes destroyed after being removed from the machine to prevent bank staff from misusing them). In some cases, the customer's PIN may be changed using the machine.
Some ATMs use smartcards to store customer data.
Most ATMs are connected to interbank networks, enabling people to withdraw and deposit money from machines not belonging to the bank where they have their account. This is a convenience, especially for people who are travelling: it is possible to make withdrawals in places where one's bank has no branches, and even to withdraw local currency in a foreign country, often at a sport ter exchange rate than would be available by changing cash. Some examples of interbank networks include Hong Kong's JETCO and the Philippines' Expressnet.
ATMs rely on authorization of a transaction by the card issuer or other authorizing institution via the communications network.
In science and technology
* Automated teller machine, cash dispenser or cash machine
* Asynchronous Transfer Mode, telecommunications protocol used in networking
* Alternating Turing machine, model of computation used in theoretical computer
* Apollo Telescope Mount, solar observatory attached to Skylab, the first US
* Amateur Telescope Making, the series of three books by Albert Graham Ingalls
* amateur telescope maker, person engaged in the hobby of Amateur telescope
* Atmosphere (unit) ("atm"), unit of atmospheric pressure
* Adobe Type Manager, typeface management software from Adobe Systems
* Ataxia telangiectasia mutated, protein kinase that plays a role in response
to DNA damage
* Azithromycin an azalide, subclass of macrolide antibiotics
People and organizations
* Altamira Airport (IATA airport code "ATM"), airport in Brazil
* Andrew Martin Andrew "Test" Martin, deceased Canadian professional
* "Angkatan Tentera Malaysia", which, translated to English means
Malaysian Armed Forces or Malaysian Military Forces but more commonly known
as the latter
* Association of Teachers of Mathematics, a UK teacher organisation
* Auto Transportes Mante, Linea de Autotransportes Tamaulipeca Mexico
* Azienda Trasporti Milanesi, public company responsible for public transportation
* "Able Toastmaster", used as a postnominal for people granted
awards from Toastmasters International
* Active Traffic Management, motorway scheme on the M42 in England
* Actun Tunichil Muknal, cave in Belize of interest in Mayan archaeology
* Adobe Type Manager, a computer program for managing fonts
* Aggregate Trailer Mass, the total mass of a fully laden trailer
* Asian Tiger Mosquito (Aedes albopictus)
* Ass to mouth, a type of sexual act
* At-the-money, term used in option pricing
* Internet slang for "at the moment"
* Midlands Gateway, ATM Gateway, Athlone, Tullamore, Mullingar Gateway or Midlands
* Awareness Through Movement, group lesson in the Feldenkrais method
* Automatenmarken, (German) gummed or self adhesive label for postal use
* ATM (computer)