In 1966, he patented personal identification number (PIN) technology and an automated teller machine (ATM).
His system accepted a machine readable encrypted card, with a numerical PIN keypad.
[3] In 1967, the world's first ATM was at Barclays Bank in Enfield, north London, which used a rival design by John Shepherd-Barron of De La Rue that accepted cheques impregnated with a radioactive chemical.
I invented an automated system with an encrypted card and a pin number, and that's the one that is used around the world today," he said.
[3] In 2011, BBC Radio Scotland broadcast Goodfellow's oral account of the history of his invention, rebroadcast in 2022.