# ESIM

An eSIM (embedded SIM) is a form of SIM card that is embedded directly into a device as software installed onto a eUICC chip. First released in March 2016, eSIM is a global specification by the GSMA that enables remote SIM provisioning; end-users can change mobile network operators without the need to physically swap a SIM from the device. eSIM technology has been referred to as a disruptive innovation for the mobile telephony industry. Most flagship devices manufactured since 2018 that are not SIM locked support eSIM technology; as of October 2023, there were 134 models of mobile phones that supported eSIMs. In addition to mobile phones, tablet computers, and smartwatches, eSIM technology is used for Internet of things applications such as connected cars (smart rearview mirrors, on-board diagnostics, vehicle Wi-Fi hotspots), artificial intelligence translators, MiFi devices, smart earphones, smart metering, GPS tracking units, database transaction units, bicycle-sharing systems, advertising players, and closed-circuit television cameras. A report stated that by 2025, 98% of mobile network operators were expected to offer eSIMs.
The eUICC chip used to host the eSIM is installed via surface-mount technology at the factory and 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. 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. One common physical form factor of an eUICC chip is commonly designated MFF2. All eSIMs are programmed with a permanent eSIM ID (EID) at the factory, which 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.
The GSMA maintains two different versions of the eSIM standard: one for consumer and Internet of things devices and another for machine to machine (M2M) devices.

## History

In November 2010, the GSMA began discussing the possibility of a software-based SIM.
In March 2012, at the meeting of the European Telecommunications Standards Institute, Motorola noted that eUICC is geared at industrial devices, while Apple foresaw eSIMs in consumer products.
A first version of the standard was published in March 2016, followed by a second version in November 2016.
In February 2016, Samsung released the Samsung Gear S2 Classic 3G smartwatch, the first device to implement an eSIM.
In March 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).
In September 2017, Apple first introduced eSIM support 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 iPhone 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), iPad Pro (7th generation), and iPad Mini (7th generation), announced in 2024, work exclusively with eSIM.
In October 2017, Google unveiled the Pixel 2, the first mobile phone to use an eSIM, available via its Google Fi Wireless service. In 2018, Google released the Pixel 3 and Pixel 3 XL and in May 2019, the Pixel 3a and Pixel 3a XL, with eSIM support for carriers other than Google Fi. In October 2019, 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.
In July 2018, Plintron implemented the eSIM4Things Internet of things product.
In December 2017, Microsoft launched its first eSIM-enabled device, the Microsoft Surface Pro LTE. In 2018, Microsoft also introduced eSIM to the Windows 10 operating system.
Samsung shipped the Samsung Galaxy S21 and S20 in North America with eSIM hardware onboard but no software support out of the box. The feature was enabled with the One UI version 4 update in November 2021.
In June 2018, Singapore sought public consultation on introducing eSIM as a new standard.
In 2023, there were 650 million installed devices with eSIM capability.

## Advantages and disadvantages
### Advantages

* Several SIMs can be stored at the same time.
* There is no need to obtain, store, and insert/eject (and potentially 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.
* Users can update to a new plan or switch carriers instantly online.
* eSIMs are better suited for Wi-Fi hotspots due to seamless network switching and enhanced security.
* The eSIM chip is half the size of the smallest physical SIM card, allowing phone designers to use space for other applications.
* eSIMs provide cost savings when traveling internationally.

### Disadvantages

* eSIMs cannot be easily transferred to another phone; the process usually requires technical support. 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 when it is sold or disposed.
* There may be compatibility issues with some phones.
* An eSIM cannot be physically removed from a device, which some might view as a disadvantage if they are concerned about being tracked.
* The implementation of the eSIM on the Samsung Galaxy series 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, because the CSC codes correspond to a single carrier.
** If a phone is bought directly from a carrier with a SIM lock, 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.