Automated Teller Machines may not seem that complicated, but they are actually a feat of engineering that required many parts from many different industries. Because of its complexity, its invention cannot be attributed to one single inventor. ATMs started with very limited functionality. The first ATM only dispensed certain amounts of cash and required a bank coin/voucher of sorts, and did not really highlight the benefits of an ATM. It was not until debit cards allowed for instant access to one’s personal account to withdraw cash from.
Many experts believe that the propagation of ATMs was because of one American businessman though, Luther Simjian. He held many patents for many industries, but his most important patent was on a machine called the bankograph. Its purpose was to accept deposits by cash or check at any time of day. This invention did not gain traction as many people had trust issues, so it was mostly used by alley people.
A couple of years later, John Barron, an inventor, made the idea of an ATM better and created a device similar to a vending machine, except his vending machine would dispense cash. Since there were no cards during this time, Barron had to make the machine accept a paper that the machine would then read and dispense cash accordingly.
This was made even more convenient for customers when a U.S. engineer incorporated the magnetic stripe on plastic cards to use for the ATMs. This made it so that customers would be able to withdraw cash straight from their bank accounts. Citibank was the first major investor and had hundreds of ATMs installed around New York, and it paid off immensely, partly due to a blizzard that closed ATMs. This event led to the other major banks installing ATMs throughout the US.