The two acronyms eUICC and eSIM are sometimes used interchangeably. Strictly speaking, however, eUICC refers to the software (and network infrastructure) and eSIM describes the hardware.

eSIM is however widely assumed to mean eUICC.

A SIM (Subscriber Identity Module) is a contact chip containing a device’s authentication credentials, enabling that device to access a cellular network. As with eUICC, the ‘e’ in eSIM stands for ‘embedded’. Instead of the familiar removable card format, an eSIM is a vacuum-sealed chip that is soldered directly to a board within the device. This form factor is known as MFF2 (machine-to-machine form factor).

eUICC refers to a particular type of software standard deployed on a SIM card. Under the traditional UICC standard, a card can usually contain just a single mobile network operator (MNO) profile. This means that if you want to switch operators, you have to physically replace the SIM. With eUICC however, the card can host multiple profiles. You can also add, remove or manage these profiles over the air via a method called remote SIM provisioning (RSP). Network infrastructure and systems are also required to manage eUICCs.

Cost of ownership

As their IoT initiatives expand, it’s common for businesses to have large numbers of IoT devices scattered across various locations. In terms of cost-effectiveness and reliability, your best choice of mobile network operator may vary from region to region. You might also want to swap operators at some point or to upgrade your connectivity method (e.g. from 3G to 4G or 5G).

With eUICC, individual devices can receive customised profiles based on their location and usage needs. Thanks to remote SIM provisioning and the ability to have multiple profiles on a single card, it becomes much easier and quicker to swap an existing data plan for a newer, more cost-effective one. You can also disable that new profile and swap it back again if circumstances change.