What are Machine-to-Machine (M2M) SIMs?

A quick guide to M2M SIMs and what makes them different from conventional SIMs.
Maggie Murphy
November 24, 2021
Two Hologram sim cards on a marble countertop

Machine-to-Machine connectivity has been around for decades, but nowadays its offshoot—the Internet of Things (IoT)—gets more attention. While the terminology differs, the idea is the same: connected machines (or things) talk to each other and the wider internet. And M2M SIM cards are the technology that allows this talking to occur.

Learn more about M2M SIMs, what makes them different from traditional SIMs, and why they are important for IoT deployments.

Jump to the section you need:

‍What are M2M SIM cards?

What’s the difference between M2M & traditional SIMs?

Which form factors do M2M SIMs come in?

What is a SIM Application Toolkit?

What should I look for in an M2M provider?

Hologram powers M2M connectivity

‍‍What are M2M SIM cards?

M2M SIM cards — also known as IoT SIMs — are pieces of hardware embedded or inserted into devices which enable connectivity and allow devices to send and receive data across cellular networks. 

What’s the difference between M2M & traditional SIMs?‍

Traditional SIM cards were designed for consumer devices like smartphones and tablets, and while they might work to a limited degree in an M2M setting, consumer SIMs don’t provide the flexibility and connection capabilities that most machines need. M2M SIM cards are designed to send and receive data rather than voice calls and text messaging. As a result, the M2M SIM cards include these additional features:

More memory

M2M SIMs send and receive large amounts of data which is why they have greater storage capacity than traditional SIMs.


M2M SIM cards are made to endure harsh conditions such as extreme heat or cold — some can operate at temperatures as low as –40º F and as high as 221º F. Embedded M2M SIMs can also withstand vibration and corrosion. They'll keep working even in connected mining equipment underground or agricultural soil sensors in the middle of a cornfield.


The devices with M2M SIMs are often part of long-term projects where the device is not easily accessible — think rural farm, a cargo ship on the ocean, or deep underground. As a result, M2M SIM cards are made to last longer than traditional SIMs — up to 10 years or more.

Remote provisioning

In an IoT environment, most M2M SIM cards operate much more independently than traditional SIMs in consumer devices. While traditional SIMs require user interaction on the device side to activate them, some M2M SIMs can be provisioned remotely using eUICC technology. eUICC-enabled eSIMs can also store multiple SIM profiles, which can be switched out from afar when needed — like swapping out credit cards in a virtual wallet.


Many M2M SIMs offer the advantage of multi-network connectivity, meaning that you aren’t tied to a single carrier network. Instead, devices can roam across geographical boundaries and connect automatically to the best local networks as they go. For example, a vehicle tracking device can stay connected as the truck driver travels from Calais to Istanbul. 

Which form factors do M2M SIMs come in?

M2M SIMs come in every SIM form factor, so it’s easy to find one whose size and features best fit your device design and use case.

Mini SIM (2FF)

The Mini SIM is the largest removable SIM card currently in use. This SIM has been used since the mid-1990s. Today, the Mini SIM is still a good option for larger connected devices, like cars and vending machines.

Micro SIM (3FF)

The Micro SIM is significantly smaller than the Mini SIM. It’s large enough to be manageable for easy physical swapping of SIM cards, but it fits better in mid-size IoT devices like tablets and telehealth monitors.

Nano SIM (4FF)

The Nano SIM is smaller and slimmer than the Mini and Micro SIM. It’s an ideal solution for compact IoT devices, including wearable technology.

The removable form factors 2FF, 3FF, and 4FF are all good options when a human is on the installing end to assist the initial device boot and SIM provisioning process.

Embedded SIM (MFF2)

The MFF2 embedded form factor (or eSIM) provides better durability since the SIM is protected inside the device. Newer MFF2 SIMs also often include eUICC remote provisioning capabilities. Remote provisioning is beneficial for many IoT deployments, especially those with devices placed in rural areas or vehicles in motion. For example, micromobility deployments benefit from eUICC because it enables the scooters to move from city to city without issuing and installing new SIM cards.

Recommended Reading: What’s the Difference Between SIM Card Types?

What is a SIM Application Toolkit (or STK)?

A set of programmed commands, the SIM application toolkit or STK establishes guidelines for how the SIM interacts with other devices and the network. In essence, the STK establishes a basis for communication between the device and the network application. Typically, M2M SIMs are programmed with an STK that provides access to multiple networks, enabling multi-network connectivity for your devices.

Why is a SIM Application Toolkit important?

The STK has an important role to play regarding SIM control and security. It allows operators to activate a new SIM, enable and update features, and is involved in network authentication. The STK also allows the operator to refresh the SIM card, send over-the-air updates, and read the SIM status.

What should I look for in an M2M provider?

What your ideal M2M connectivity provider looks like will depend somewhat on your devices and use case — you won’t need global connectivity, for example, if your devices are dedicated in one place and you don’t plan to expand. Yet, in a changing technological and business landscape, you don’t know where your M2M project will lead in the future, so it’s wise to find a provider with strengths like these:

Simple scalability

Even if you’re only planning to use IoT to monitor a dozen machines in a small factory, you never know what the future may hold. Choosing a provider that can scale up quickly and easily is an important safeguard for your business. Ideally, find one that doesn’t require benchmarks such as contracts or quotas. That flexibility will pay off in cost savings over time.

Global Network Access

In a global business climate, making sure your M2M SIMs can connect anywhere they go is important. For example, if you’re a micromobility provider, your connected scooters will need to stay connected and trackable even if a driver removes one from its designated area. So look for a provider with a single global M2M SIM card or eUICC chip that can automatically find and connect to the best local networks, no matter where they roam.

eUICC capabilities

While you might not need remote provisioning capabilities at the moment, eUICC-enabled eSIMs are the wave of the future — and for good reason. They give you the ability to swap out SIM profiles on your devices remotely if you need to switch carriers or networks. Choosing a provider now that makes and supports eUICC technology ensures that you won’t need to go through the headache of finding a new connectivity service if you need those capabilities in the future.

Recommended Reading: eSIM vs. IoT SIM card: 5 differences explained

Easy-to-use management platform

Device and connectivity management are essential components of any M2M/IoT project. Pick a provider whose management platform is intuitive and accessible, giving you real-time visibility into the health of your fleet. Information about device usage, data limits, and connectivity status is vital, and tracking tools and alert triggers can make device management easier and more streamlined.

Clear-cut pricing

Large carriers tend to price M2M connectivity in bulky, complicated plans that can cause you to purchase more data usage than you need. On the other hand, carrier-agnostic providers are more likely to offer flexible pricing. A pay-as-you-go model works great for smaller device deployments, and the rates often go down as you add more devices.

Hologram powers M2M connectivity

Hologram specializes in M2M connectivity. Our hardware-agnostic global SIM connects automatically to the best available local networks from more than 470+ global partners. And our easy-to-use Dashboard and flexible REST API enable efficient device management. Ready to start your IoT deployment? Check out our global IoT SIM card.

Get started with Hologram today

  • Talk to an IoT expert
  • Receive a free SIM
  • Customize your plan