ESIM



An eSIM (embedded SIM) is a form of SIM card that is embedded directly into a device. Instead of an integrated circuit located on a removable SIM card, typically made of PVC, an eSIM consists of software installed onto an 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 may not support an eSIM, may have a permanently programmed, unchangeable one, or one that can be reprogrammed for any carrier 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 and network authentication key 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.

History
Since 2010, the GSMA had been discussing the possibility of a software-based SIM.

While Motorola noted that eUICC is geared at industrial devices, Apple "disagreed that there is any statement forbidding the use of an embedded UICC in a consumer product". Currently, the GSMA maintains two different versions of the standard: one for consumer devices and another for machine to machine (M2M) devices.

A first version of the standard was published in March 2016, followed by a second version in November 2016.

Implementation
In 2016, the Samsung Gear S2 Classic 3G smartwatch was the first device to implement an eSIM.

In 2017, during Mobile World Congress, Qualcomm introduced a technical solution, with a live demonstration, within its Snapdragon hardware chip associated with related software (secured Java applications).

Apple first introduced eSIM support in September 2017 with the Apple Watch Series 3. In 2018, it introduced it to iPhone, with the iPhone XS and iPhone XR, and iPad, with the iPad Pro (3rd generation). The first iPhone models to not have a SIM card tray and work exclusively with eSIM were the iPhone 14 and 14 Pro, announced in 2022. Outside the United States, all iPhone models continue to be sold with support for physical SIM cards, but the iPad Air (6th generation) and iPad Pro (7th generation), announced in 2024, work exclusively with eSIM.

Google unveiled the Pixel 2 in October 2017, which added eSIM support for use with its Google Fi service. In 2018, Google released the Pixel 3 and Pixel 3 XL and subsequently in May 2019, the Pixel 3a and Pixel 3a XL, with eSIM support for carriers other than Google Fi. In October that same year, Google released the Pixel 4 and Pixel 4 XL with eSIM support.

Motorola released the 2020 version of the Motorola Razr, a foldable smartphone that has no physical SIM slot since it only supports eSIM.

Plintron implemented the eSIM4Things Internet of things product, based on eSIM support for the devices and available in 28 countries.

Microsoft introduced eSIM to the Windows 10 operating system in 2018 and launched its first eSIM-enabled device, Surface Pro LTE, in 2017.

Samsung shipped Galaxy S21 and S20 series smartphones in North America with eSIM hardware onboard but no software support out of the box. The feature was later enabled with the One UI version 4 update. However, the implementation of the eSIM on the S21 and S20 in North America (USA and Canada) is different than the implementation in the rest of the world.
 * North American variants lack the ability to specify different default SIMs for different functions, e.g., one SIM as the default for data and the other SIM as the default for voice. They require that the same eSIM be the default SIM for data, voice, and SMS.
 * The US variants also force a reboot each time the user switches eSIMs, while other models do not, given that the CSC codes correspond to each single carrier.
 * If bought directly from a carrier, the phone can only add eSIMs from the same carrier as the one on the physical SIM card, even after a carrier unlock.
 * Foreign eSIMs may have limited support.

Design
A traditional SIM card consists of an integrated circuit located on a universal integrated circuit card (UICC), typically made of PVC, which is manually inserted into a device. By contrast, an eSIM is a virtualized SIM card profile installed onto an eUICC chip permanently surface-mounted to a mobile device at the factory. The eUICC chip used to host the eSIM uses the same electrical interface as a physical SIM as defined in ISO/IEC 7816 but with a small format of 6 mm × 5 mm. Once an eSIM carrier profile has been installed on an eUICC, it operates in the same way as a physical SIM, complete with a unique ICCID and network authentication key generated by the carrier.

Usage
An eSIM is typically provisioned remotely; end-users can add or remove operators without the need to physically swap a SIM from the device. All eSIMs are programmed with a permanent eSIM ID (EID) at the factory. This number is used by the provisioning service to associate the device with an existing carrier subscription as well as to negotiate a secure channel for programming.

Specifications
eSIM is a global specification by the GSMA that enables remote SIM provisioning of any mobile device. GSMA defines eSIM as the SIM for the next generation of connected consumer devices. Networking solutions using eSIM technology can be widely applied to various Internet of things (IoT) scenarios, including connected cars (smart rearview mirrors, on-board diagnostics (OBD), vehicle Wi-Fi hotspots), artificial intelligence translators, MiFi devices, smart earphones, smart metering, GPS tracking units, DTU, bike-sharing, advertising players, video surveillance devices, etc. eSIMs effectively resolve hotspot tethering issues, ensuring stable, seamless connectivity.

One common physical form factor of an eUICC chip is commonly designated MFF2.

The European Commission selected the eUICC format for its in-vehicle emergency call service, known as eCall, in 2012. All new car models in the EU must have one by 2018 to instantly connect the car to emergency services in case of an accident.

Russia has a similar plan with the GLONASS (national satellite positioning system) called ERA-GLONASS.

Singapore is seeking public opinions on introducing eSIM as a new standard, as more compatible devices enter the market.

Advantages

 * Several SIMs can be stored at the same time.
 * No need to obtain, store, and insert/eject (and lose) small physical SIMs.
 * If the phone is stolen, it can be tracked by "find my phone" services, while a physical SIM can be removed.
 * The risk of damaging a SIM socket's delicate contacts inserting and removing a SIM is eliminated.
 * Phones with eSIM only do not need to be built with hardware SIM holders or means to insert them. This is particularly relevant for small devices such as smartwatches.
 * eSIMs offer immediate activation and connectivity since numbers are assigned Over-The-Air (OTA), eliminating any wait time typically associated with traditional SIM cards.

Disadvantages

 * If a phone is broken, anything restricted to the eSIM's network becomes inaccessible; in particular, calls cannot be received, and resources (calls, SMS, data) paid for cannot be used. A physical SIM can be transferred from a broken to a working phone.
 * The eSIM, which allows communications to be made and charged to the account-holder, cannot be removed if having the phone repaired, or lending it to someone.
 * eSIM accounts must be deleted or transferred from a phone which is sold or disposed of.
 * Compatibility issues with some phones, e.g. US phones that do not accept eSIMs from other countries.
 * Transferring eSIMs from one device to another can require support from the user's carrier, such as from an Android device to an iPhone.