How do cash machines work?

It’s somewhat hard to imagine our modern world without cash machines, yet they only became the norm during the 1970s. The first machine that dispensed cash was invented by John Shepperd-Barron and was installed outside a branch of Barclays Bank in Enfield, Greater London.

Today, they work to give us access to our money 24 hours a day in a multitude of locations, and are far more convenient than queuing in a bank. However, there are many challenges for them to overcome in order to provide the required level of service. They have to check that you and your card are legitimate, find your account information and carry out the transaction required, all while protecting the thousands of pounds stored inside its vault.

The magnetic strip on the back of your card may look like a solid black line, but it’s actually composed of millions of tiny magnets, each one magnetised either north or south, which two magnetic readers understand like a binary code. The first reader confirms the card is real, while the second reads your account number and PIN, checking this against the code that you entered on the keypad.

Once your PIN is confirmed, the machine automatically connects to your bank’s network which relays a signal back to the built-in vault, giving it a specific set of instructions. The ATM will then complete the transaction that has been requested. If you forget to take your cash for whatever reason, modern cash machines will swallow the money after a short period of time so you won’t be out of pocket.

Cash machine

How do cash machines work?

The rise of ATM fraudsters

Today our cash machines are constantly under threat from organised crime, with a number of techniques available to criminals that can quickly and cheaply access your card details. The skimmer attachment is one of the most commonly used scams, and involves a small device being fitted to the cash machine which will then read and record your card details. Coupled with this is often a hidden camera, cleverly concealed in panels above the machine or somewhere nearby to find out what your PIN code is. Card traps are also becoming increasingly popular – they work by trapping your card in the machine for the fraudster to collect at a later date. To combat these problems, the police recommend that you always remain vigilant when using a cash machine. By checking for anything unusual or out of the ordinary, you can spot most attempts to rip you off, especially if you use the cash point in question frequently. Make sure you cover your PIN at all times and be wary of any suspicious bystanders hanging around the ATM.

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