There are about 3.5 million ATMs available world-wide, but the number differs across regions. In the Asia-Pacific region, ATM usage has not taken off as the advent of mobile banking and electronic banking has superceded ATM usage. In established first world countries, ATMs remain stable and should remain so until the advent of a technology like Bitcoin removes the need for fiat currency.

Generally ATMs are used via plastic cards, with a three digit PIN code to activate.

The first ATM ever created was by Barclay's and located in the Enfield branch.

ATMs authorize a financial transaction by the card issuer or another authorizing institution. This is usually done via an ISO 8583 messaging system