eSIM (embedded SIM) is a soldered chip inside a device that stores subscriber identity data, performing the same role as a removable physical SIM card. The chip itself is fixed; carrier profiles are downloaded over the air. eSIM has been widely deployed in flagship smartphones since 2018, in Apple Watch and cellular iPad lines, and in growing categories of IoT devices.
For wholesale buyers, eSIM matters because spec regions have diverged. From iPhone 14 onward, US-spec iPhones are eSIM-only (no physical SIM tray). EU-spec, GCC-spec, HK-spec, and most other regional variants retain physical SIM trays, typically with a dual SIM (one physical + one eSIM) configuration. A US-spec iPhone 14+ sold into a market expecting physical SIM is functionally limited.
Operational consequence: when sourcing iPhone wholesale, the FCC ID and model number determine the SIM configuration. Buyers servicing markets with limited eSIM carrier support (most of Africa, parts of South-East Asia, large stretches of Latin America) should explicitly avoid US-spec iPhone 14 and later. The same eSIM-only constraint affects Samsung Galaxy S-series in some US carrier variants from 2024 onward.