IoT Nano SIM VS eSIM: What’s the Difference?

The main difference between eSIM and nano-SIM lies in their form factors, with eSIM being an embedded SIM/ SIM chip (MFF2: 5mm x 6mm x 1mm) soldered into the device, while a nano-SIM is a removable SIM card (12.3mm x 8.8mm x 0.67mm) inserted into a compatible SIM card slot. However, in terms of eSIM, the meaning is a bit more complicated. 

What Is a Nano SIM? 

A nano SIM is one of the formats or forma factors of a SIM and IoT SIM. It’s also known as 4FF and is the fourth generation of SIM cards, being only 12.3mm x 8.8mm x 0.67mm.  It requires a smaller SIM card slot, providing greater design flexibility for modern smartphones and IoT devices. Nano SIMs are only available in commercial grade, which may not be suitable for industrial applications with extreme conditions. 

eSIM and eUICC Confusion 

eSIM is a broader and more confusing notion nowadays. It can be referred to as a SIM chip or MFF2 form factor, which is embedded within IoT devices by soldering it onto the circuit board. At the same time, it’s often used interchangeably with eUICC. An eUICC-enabled SIM card, regardless of its form factor, incorporates technology and software for remote provisioning of carrier profiles, eliminating the need for physical card replacement. eUICC allows for over-the-air (OTA) management, enabling, disabling, and downloading of Mobile Network Operator (MNO) profiles. In contrast, traditional SIM cards lacking this technology would require physical replacement with another operator's SIM card. If compared to Soft SIM, it’s more logical to view it as a format in this particular case.  Unlike traditional SIM cards, eSIMs (MFF2) are resilient to vibrations, movement, moisture, and corrosion. As a result, MFF2 IoT SIM chips have become an ideal solution for verticals like the utility sector and consumer electronics. 

What Are the Differences between Nano SIMs and eSIMs (MFF2)? 




Form Factor 

12.3mm x 8.8mm x 0.67mm 

MFF2 embedded in device, 5mm x 6mm x 1mm 

Physical Swapping 

Requires manual insertion/removal 

No physical swapping required 

Device Compatibility 

Requires compatible SIM card slot 

Requires eSIM-capable devices 

International Roaming 

May require purchasing local SIM if it doesn’t contain eUICC tech 

Usually can access multiple networks 

Flexibility and Convenience 

Less flexible, may need physical replacement 

Highly flexible, remote activation and switch between carriers 


Device lifespan may necessitate SIM replacements 

Long-lasting, for device lifetime 

Protection from Theft 

Removable and vulnerable to theft 

Embedded and less vulnerable to theft 

1NCE Shop

Buy the 1NCE IoT Lifetime Flat now

Visit the 1NCE Shop and start connecting your IoT devices easily. Simply order your SIM cards, choose the desired type of SIM card and fill out all required forms. After the payment has been approved you get your cards within five to seven business days.