ESIM
Introduction


[alt\=Comparison of SIM card sizes\|thumb\|Evolution of SIM cards. An eSIM is not removable.](/wiki/File:SIM_card_sizes.png "SIM card sizes.png")

An **eSIM** (**embedded SIM**) is a form of [SIM card](/wiki/SIM_card "SIM card") that is embedded directly into a device. Instead of an [integrated circuit](/wiki/Integrated_circuit "Integrated circuit") located on a removable SIM card, typically made of [PVC](/wiki/Polyvinyl_chloride "Polyvinyl chloride"), an eSIM consists of software installed onto a [eUICC](/wiki/EUICC "EUICC") chip permanently attached to a device. If the eSIM is eUICC\-compatible, it can be re\-programmed with new SIM information. Otherwise, the eSIM is programmed with its ICCID/IMSI and other information at the time it is manufactured, and cannot be changed. Different [mobile telephones](/wiki/Mobile_telephone "Mobile telephone") may not support an eSIM, may have a permanently programmed, unchangeable one, or one that can be reprogrammed for any [carrier](/wiki/Mobile_network_operator "Mobile network operator") that supports the technology. Phones may support physical SIMs only, eSIM only, or both.

Once an eSIM carrier profile has been installed on an eUICC, it operates the same as a physical SIM, complete with a unique [ICCID](/wiki/SIM_card "SIM card") and [network authentication key](/wiki/SIM_card%23Authentication_key_%28Ki%29 "SIM card#Authentication key (Ki)") generated by the carrier.

The eSIM standard was first released in 2016; since that point, eSIM has begun to replace physical SIM in domains including cellular telephony.


How does the switch to eSIMs affect the mobile phone industry?