What are eSIMs? Here’s everything you need to know

A SIM card, or Subscriber Identity Module, as the name implies, is a form of a digital ID card that your phone, tablet, smartwatch, or other cellular devices require to gain access to mobile networking services. The SIM card stores a unique identification token called the International Mobile Subscriber Identity (IMSI) and uses that to authenticate itself on your telecom service provider’s (TSP) network. 

SIM cards come in various sizes, with the most popular one available today being the nano SIM. These SIM cards are purchased from TSPs and inserted into a cellular device to enable access to cellular networks for making calls, streaming data, etc.

What is an eSIM?

A few years ago, mobile device makers started offering eSIMs or embedded-SIM cards, often incorrectly referred to as electronic-SIMs, with smartphones and other cellular devices. Unlike traditional SIM cards, which are plastic coated integrated circuit boards that you must insert into your mobile devices, eSIMs are soldered onto the chipset directly by the manufacturer. 

ALSO READ: How to setup eSIM on iPhone

In a smartphone, chipset refers to the integrated circuit board that houses the various processors (CPU, GPU, NPU, etc.), memory (internal storage and RAM), and other electronic components such as the cameras, speakers, and more, that your phone needs to function.

Advantages of eSIMs

Owing to their design, eSIMs offer the following advantages over physical SIM cards.

1. Smaller footprint: Given their size, and the fact that eSIMs are soldered directly onto the chipset, eSIMs occupy much less space inside a smartphone, freeing up room for additional electronics and simplifying the design of the chipset.

2. Simpler and more durable: Additionally, the frame of your phone or mobile device need not have a hole cut into it for a physical SIM card and SIM tray, improving water and dust resistance and reducing manufacturing cost slightly.

3. Reduced cost: Since eSIMs are embedded into the mobile device, activating your cellular connection is simpler and cheaper as the process can be completed online or sometimes with just an activation code. The environmental impact is also lower as you’re not only reducing plastic use, but also saving on packaging costs and time.

4. Greater flexibility: eSIMs simplify connectivity and interoperability within cellular networks. Where a traditional SIM can hold only one IMSI profile, an eSIM can hold up to eight, allowing you to swap between up to eight numbers/carriers. This can be especially useful if you travel frequently. Do note that at the moment, only two profiles can be active at a given time.

5. Enhanced security: In the unfortunate event that your device is stolen, thieves cannot immediately clone your SIM, swap it out, or even disable it to prevent tracking. On top of that, software updates can help continuously mitigate any workarounds that are discovered over time.

One downside to eSIMs over physical SIMs is that the switching process is a little tedious if you’re someone who needs to often swap between devices. The carrier will need to be informed, a code will need to be generated, and then the swap can happen. Another issue is that not all carriers support eSIM even today. Major carriers internationally and in India support the feature, but some of the smaller ones in India and abroad do not, which can be inconvenient for some.

eSIMs vs iSims

eSIMs are great, but iSIMs could be the future.

eSIMs are gaining popularity and can be found on a lot of phones today. The inevitable evolution of the SIM card, however, is likely to be the iSIM (and no, we’re not talking about an Apple-branded SIM card). Where an eSIM is an independant chip that is soldered onto your smartphone’s chipset, an iSIM or integrated SIM is one that is designed and manufactured as part of the chipset.

Given that it is part of the chipset itself, an iSIM offers even greater flexibility while occupying even less space and consuming much less power. Popular chipsets like the Qualcomm Snapdragon 8 Gen 1 and Gen 2 already feature an iSIM.  eSIMs are already taking over, but it’s likely only a matter of time before the iSIM replaces it.