Different Types of SIM Cards: Considerations of the Differences and How to Choose

The number of IoT devices is growing rapidly worldwide. SIM cards are changing too. In the past, people used different types of SIM cards (like Mini/Nano SIM). Now, some devices use SIM cards soldered to the motherboard (MFF2 SIM). There is also a new type called eSIM, which can be set up remotely. Many device makers and customers ask: Which SIM is best for my device?

This article will explain the differences between Nano SIM, MFF2 SIM, and eSIM. You will learn their pros, uses, and how they work in real devices. We will also share examples from Minew Cellular products. This will help your team give better advice to customers.

Understanding of Different Types of SIM Cards

Nano SIM

Nano SIM is the most widely used removable SIM card today. Its small size and wide compatibility make it a top choice for many devices.

Key Features:

• Size: 12mm x 9mm (about 40% smaller than older Micro SIM cards)
• Common Uses: Smartphones, tablets, IoT devices (like smartwatches or trackers), and prototype testing.
• Flexibility: Users can easily swap the SIM card between devices. For example, you can take it out of an old phone and put it into a new one.
• Reliability: Physical insertion ensures stable network connections in most environments.

Why It’s Popular?

Nano SIM works with almost all consumer electronics. Its standard design reduces manufacturing costs. It is also easy to test new devices during development – engineers can quickly replace SIM cards without special tools.

Limitations:

• Requires a SIM tray slot, which takes up device space.
• Not ideal for devices exposed to water, dust, or vibrations (e.g., industrial sensors).

MFF2 SIM

The MFF2 SIM is soldered directly onto a device’s motherboard during manufacturing. Unlike removable SIM cards, it cannot be replaced after installation.

Key Features:

• Size: 6mm x 5mm (50% smaller than Nano SIM, ideal for ultra-compact devices).
• Common Uses: Smart wearables (e.g., fitness bands), asset trackers, industrial equipment (like factory sensors or security cameras), and devices requiring anti-tampering features.
• Anti-Tamper Design: Once welded, it resists physical removal or tampering. This makes it perfect for security-focused applications.
• Durability: Withstands harsh conditions like extreme temperatures, vibrations, and moisture.
• Automation-Friendly: Fits seamlessly into automated production lines, reducing assembly time and human errors.

Why Choose MFF2?

This SIM type saves critical space in tiny devices. For example, a smart medical patch can’t fit a Nano SIM slot. Its permanent installation also prevents theft or misuse in public devices (e.g., shared bikes). Manufacturers like Minew use MFF2 SIMs in GPS trackers to ensure reliability in rugged environments.

Limitations:

• No user replacement – if the SIM fails, the entire device may need repairs.
• Higher upfront cost for equipment and specialized production processes.

eSIM

eSIM is a SIM chip built into devices that can be programmed remotely. Unlike traditional SIM cards, it uses over-the-air (OTA) updates to switch carrier profiles without physical replacement.

Key Features:

• No Physical Card: No SIM slot needed – saves space for slimmer designs (e.g., foldable phones).
• Remote Management: Users can switch carriers or plans via software. For example, travelers can buy a local data plan without buying a new SIM.
• Global Flexibility: Supports multiple carrier profiles, ideal for devices used across countries (e.g., logistics trackers or connected cars).
• Standard Compliance: Follows GSMA SGP.31/32 standards, ensuring compatibility with major carriers like Vodafone and AT&T.

Why Choose eSIM?

It simplifies device design and logistics. A smart thermostat using eSIM can activate service automatically after installation. Minew’s eSIM-enabled sensors allow customers to manage global deployments from one platform. Car manufacturers also use eSIMs to provide connected car services without regional SIM restrictions.

Limitations:

• Requires carrier support for remote provisioning (not all operators offer this).
• Device must have eSIM hardware pre-installed, limiting retrofitting options.

What Are the Differences of Several Types of SIM Cards

All three SIM types can work worldwide. But Nano SIM and MFF2 SIM need extra support:

• You must use a global roaming plan, or
• Choose a virtual carrier plan that already covers multiple countries.

And eSIM works differently. It uses an eUICC platform. This platform lets you add or switch carriers remotely. No physical changes are needed.

How to Choose From Different Types of SIM Cards

Here are some tips that can help you choose the right types of Sim cards:

If your customer wants to replace SIM cards easily (for device testing or switching carriers), Nano SIM is recommend:

• Users can swap cards manually.
• Best for devices needing frequent updates or trials.

If the device is for long-term use (anti-tamper design + mass production), MFF2 SIM is recommend:

• Soldered to the board – no physical removal.
• Works perfectly with automated SMT assembly lines.
• Reduces manual labor and errors.

If the device needs global coverage or remote carrier switching, eSIM is the solution (but costs more):

• Uses eUICC platforms to manage carriers remotely.
• Requires partnerships with eSIM service providers.

Two Key Standards to Judge eSIM

To confirm if a device uses real eSIM (not a soldered SIM), check these two requirements:

1. Does It Follow GSMA eUICC Standards?
   1. Real eSIM must use an eUICC platform.
   2. This lets you download and manage carrier profiles remotely (via servers like SM-DP+).
2. Can It Switch Carriers Remotely?
   1. The device should automatically switch to local networks when used in different countries.
   2. Example: A tracker in Germany connects to Deutsche Telekom, then switches to Verizon when shipped to the US.

Important: Only devices that meet both requirements are true eSIM. If not, it’s just a soldered SIM card.

Benefits of SIM Cards for IoT Devices:

1. Wide Device Compatibility

SIM cards have been the industry standard for decades, ensuring seamless compatibility with most IoT devices.

Nano SIM: Works with smartphones, tablets, and legacy IoT devices (e.g., smart meters, GPS trackers).

MFF2 SIM: Designed for compact devices without SIM slots (e.g., wearables, industrial sensors).

eSIM: Requires eUICC-enabled hardware but is becoming common in newer devices (e.g., connected cars, smart cameras).

2. Global Connectivity

Nano SIM & MFF2 SIM: Pair with global roaming plans or multi-country virtual operators.

eSIM: Automatically switches to local carriers via remote profiles (e.g., a logistics tracker in Japan uses SoftBank, then switches to T-Mobile in the U.S.).

3. Easy Scalability

Nano SIM: Swap cards manually for testing or upgrades (e.g., replace a SIM in a prototype device).

eSIM: Update thousands of devices remotely (e.g., deploy new data plans to smart city sensors via software).

4. Strong Security

MFF2 SIM: Tamper-proof design for public devices (e.g., prevents SIM theft in shared bikes).

eSIM: Encrypted carrier profiles block unauthorized access (e.g., protects medical IoT devices from hacking).

5. Cost Efficiency

MFF2 SIM: Reduces assembly costs through automated SMT production (e.g., no manual SIM insertion).

eSIM: Avoid roaming fees by activating local profiles (e.g., a smart thermostat uses cheaper regional data plans).

6. Durability

MFF2 SIM: Built to withstand extreme conditions (e.g., factory vibrations, outdoor weather).

eSIM: No physical card to damage (e.g., ideal for ruggedized field equipment).

Minew’s SIM Card Strategy

Minew uses Nano SIM and MFF2 SIM flexibly across different scenarios:

Nano SIM (Removable)

• Current Usage: The most widely adopted SIM type.
• Best For:
  • Prototype testing and pilot deployments.
  • Customers needing post-deployment SIM replacement (e.g., field-upgradable devices).
• Advantages:
  • Universal compatibility.
  • Easy to source and replace.
  • Our default option for most customers.

MFF2 SIM (Embedded)

• Best For:
  • Tamper-proof, long-term deployments.
  • Mass-produced devices requiring automated assembly.
• Ideal Scenarios:
  • Disposable trackers (e.g., logistics tags).
  • Cold chain monitoring tags (no SIM replacement needed).

Custom Solutions

• Minew offers flexible SIM strategies. We can switch between Nano SIM and MFF2 SIM based on your project needs.

Conclusion

Nano SIM, MFF2 SIM, and eSIM each serve unique roles in IoT connectivity. Nano SIM offers flexibility for testing and replaceable devices, while MFF2 SIM ensures durability and cost-efficiency for long-term deployments. eSIM enables global scalability through remote management. Choosing the right SIM depends on your device’s environment, security needs, and operational scale. For tailored IoT solutions, Minew provides adaptable strategies with Nano and MFF2 SIMs, ensuring seamless integration and future-ready performance.