A SIM card stores your subscriber identity data, which is needed to connect to a carrier's network. But do you still need one in 2025?

The power of the SIM The use of contact smart card SIMs with GSM adds a much more robust security solution and means to authenticate users. “The SIM card is a tamper-resistant IC card that is built to ...

How Does Unlocking SIM Cards Work?. After you purchase and use your cellphone for an extended period of time, you can change networks.

With the updated Find My Device, Google now lets you locate your Android phone, tablet, or even headphones, without needing a SIM card or active internet.

SIM cards link accounts to handsets. They keep communications private. They store messages. Although small and simple, they are a big part of modern mobile phone systems.