Where Did SIM Cards Come From?: The Story Behind Mobile’s Smallest Powerhouse

That tiny plastic card you insert when setting up a new phone or switching devices— it’s called a USIM (Universal Subscriber Identity Module) . Though it seems minor, this card is the heart of mobile connectivity. But have you ever wondered where it came from? Today, we’ll take a historical look at how SIM cards were born, evolved, and became the backbone of mobile communication.     1. The Rise of Mobile Phones and the Need for Subscriber Identity Before the 1990s, mobile communications relied on device-based authentication . That meant your phone was tied to the network itself—changing devices required visiting a telecom store. As technology progressed, people wanted to keep their number while changing devices . This led to the introduction of the GSM (Global System for Mobile Communications) standard— and with it, the debut of the SIM card. 2. The Birth of the SIM Card: GSM’s Breakthrough In 1991, Europe launched the first commercial...