Bank Card Standardization Sets Rectangular Shape

All bank cards—ATM, credit, and debit—share a rectangular form with rounded corners. The shape originated with early payment cards such as the 1950 Diners Club, which were first made of cardboard before moving to plastic in the 1960s. The need to display embossed information and later to carry magnetic‑stripe data (developed by IBM in the 1960s) required a flat, wide surface that could be easily handled and read by machines.

To avoid incompatibility among banks, merchants, ATMs and wallets, the payment industry adopted the ID‑1 size defined in the ISO/IEC 7810 standard. This global specification fixes the dimensions of modern bank cards, ensuring that devices worldwide can process them reliably.