What is eSIM, Chip SIM, Embedded SIM, Multi-IMSI SIM, iSIM? Status of eSIM functionality in South Africa.

Modified on Tue, 11 Jul 2023 at 01:14 PM

There is often some confusion around these terms within the industry.
The terms can refer to the physical form of the SIM (form factor) or the set of SIM capabilities.

What is the Difference between eSIM and Embedded SIM in IoT?

What is a SIM?

A SIM (Subscriber Identity Module), also called a Universal Integrated Circuit Card or UICC, stores information that uniquely identifies a cellular subscription.  It holds the credentials and security keys necessary to identify a subscriber. That identity comes in the form of a so-called IMSI number, or International Mobile Subscriber Identity, which is unique for every user or device on or off the network. SIMs also run an application that passes that identity information to an onboard cellular modem. The modem in turn conducts the actual attachment operation to the network. The application that the SIM card runs, by the way, is also referred to as UICC; the acronym is often used synonymously with the card or chip itself.

The rightmost one looks a little different – that’s because this is a chip soldered directly onto your electronic circuit board that makes up your device, vs. the bigger versions you insert manually into a slot. This smaller form factor was needed for our ever-shrinking consumer and IoT devices. You could say it is “embedded” into a bigger circuit board. Embedded SIM formats are available from us for most local and mobile networks.

So if the MFF2 form factor is “embedded”, is this tiny SIM what we call an “eSIM”? Unfortunately, no. Some do, but it’s imprecise. While the “e” in eSIM does stand for embedded (you will also find the reading “electronic SIM” out there), what is meant with eSIM is really a different “kind” of embedded – not the hardware kind.

What is an eSIM?

In simple terms, an eSIM is a SIM that can load new carrier profiles digitally, over the air, which means you no longer need to physically swap SIM cards in your devices.

In more technical terms, an eSIM is any piece of hardware that runs an application called eUICC, which has storage to hold multiple SIM profiles at the same time (but only one can be active), and can be provisioned remotely, over the air (OTA).

An eSIM doesn’t need to come along only in the form of any of the known form factors (2FF, 3FF, 4FF, MFF2) – anyone can design their own hardware chip, as long as it runs an application that conforms to the eUICC standard

Status of eSIM functionality in South Africa:
Networks in South Africa (Vodacom, MTN, Telkom) only support eSIMs installed in a set list of consumer devices, and charge a premium for this capability. They also need to be programmed manually on the device (not Over The Air), typically by using an app. The devices need to be on the list of allowed eSIM devices for each network. The costs to enable eSIM for IoT devices is currently too high to make commercial sense and is therefore not supported at present.

For IoT devices, no local remote eSIM activation support is available on South African networks.

For consumer devices, the following sSIM support is available:

UPDATE: From 19 June '23, Vodacom also offers eSIM activation on Prepaid and Top-Up tariffs.
Once-off charges:

Vodacom eSIM Activation Procedure:

Q: How do you activate eSIM?

A: Only via QR code initiated at a Vodacom Store. Prepaid customers will receive the QR code via a

till/POS slip and a Postpaid / Hybrid customers will receive it via the default email address on the

system/their account.

Q: Will the Vodacom eSIM work if the handset was not purchased directly from Vodacom

A: Vodacom eSIM will work on smartphones that are/were sourced (bought/taken through a

contract) from Vodacom or bought from another provider within the OEM approved region].

Note! Some devices that were sourced outside South Africa may not work with the Vodacom eSIM,

this could be because of how the device is managed from the source location and could be because

of regional based locks. In this case the customer will need to contact store/location where the

device was received from as Vodacom is not able to. An error will be displayed on such devices if a

Vodacom eSIM is not compatible.

Please see complete Vodacom eSIM Q&A attached (Below).

Article: eSIM support in South Africa — A sad affair of limited options


Multi-IMSI is a concept developed to overcome the single profile limitation set by UICC. The Multi-IMSI packages multiple MNO profiles (IMSI) in a single SIM card. The MNO profiles are managed by an applet running on the SIM

The applet allows remote management and control of the MNO profiles (add/remove/provision). These are typically user for roaming between mobile networks.


The next revolution in the eSIM world wil be the iSIM (aka integrated SIM), a SIM that integrates directly into the device's processor.

 In essence, the iSIM enables devices to connect to a cellular network without needing a physical SIM card or soldered eSIM in a printed circuit board. 

Instead of using a separate physical SIM card, the iSIM technology embeds the SIM features directly into the device's hardware, allowing it to connect to the cellular network.

The iSIM offers two key features: 

- It saves space by eliminating the need for a separate component.

- It requires significantly less power than eSIMs, making, for example, massive IoT use cases more operational.

Please contact us for embedded or Multi-IMSI SIM options for IoT deployments. 

tags: eSIM, e-SIM, chip SIM, embedded SIM, multi-IMSI, eSIM Vodacom , eSIM MTN, eSIM South Africa, eSIM IoT.
Sources: Wikipedia, MyBroadband, Twillio. 

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