Guide to M2M SIM Cards

Velos IoT is a leader in IoT (Internet of Things) connectivity, helping enterprises worldwide to jumpstart their digital transformation and embrace a connected future. M2M SIM cards are the primary piece of hardware that enables device-level IoT connectivity and are a core element of our technology suite. We can help you understand them.

What is an M2M SIM Card?

M2M is an abbreviation for “machine-to-machine.” Devices with M2M SIM cards can send and receive data across cellular networks. In IoT devices, the M2M SIM may share data directly with other devices and the software that manages the platform. Therefore, the terms “M2M SIM” and “IoT SIM” are often used interchangeably.

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Differences Between M2M SIMs & Standard SIMs

When most people think of SIM cards, they think of the SIM card in a phone. M2M SIMs operate using the same wireless cellular networks, but they offer benefits that standard mobile SIM cards do not:

  • M2M SIMs are durable. Depending on the form factor, they can last for years, even in harsh environments.
  • M2M SIMs are remotely manageable. While standard SIMs keep a device connected to a network, M2M SIMs can be activated, controlled, and monitored in bulk, depending on the IoT management platform you’re using.
  • M2M SIMs support data plan aggregations. Every SIM added to an IoT project increases the project’s data cap, which helps keep IoT connectivity affordable and cost-effective.
  • M2M SIMs may have fixed IP addresses. Devices with a fixed IP address can be accessed more reliably and securely, regardless of location.

Because of these qualities, M2M SIMs are a perfect match for many industrial and commercial IoT applications. Moreover, they’re available in many different form factors suitable for a full spectrum of smart devices.


Different Types of M2M SIM Cards

M2M SIM cards differ in form factor (size), network roaming, and functionality.

IoT SIM Card Form Factors

Here’s a convenient overview of the different M2M SIM shapes and sizes:

  • Full-Size (1FF) is the largest M2M SIM card, about the size of a credit card. For the most part, it has been phased out by smaller, modern SIMs.
  • Mini-SIM (2FF) is the industry standard SIM card size, measuring 25mm x 15mm x 0.76mm. It’s typically used in devices like vehicles, vending machines, and payment points.
  • Micro-SIM (3FF) – The micro-SIM is half the size of the mini and is used in portable devices like tablets, GPS, health trackers, and other mobile IoT devices.
  • Nano-SIM (4FF) – The nano-SIM is 40% smaller than the micro variation, making it great for small IoT devices. These SIMs have relatively little protection so they’re not recommended for harsh environments.
  • Embedded SIM (MFF2) – Embedded SIMs, also known as eSIMs, measure only 6mm x 5mm x 1mm. These are the most popular IoT SIM because of their convenient size and durability. They’re typically soldered directly to devices, so they need to last a long time.

Types of M2M SIM Roaming

IoT devices typically require SIM cards that can roam across multiple cellular networks. There are two types of multi-network open roaming:

  • Steered SIMs have a network preference. Steered M2M SIMs defer to one specific provider network, even if a stronger network is available, unless they are completely out of range.
  • Non-steered SIMs connect to the strongest network available. It’s critical to use non-steered SIMs when constant connectivity is crucial, such as in healthcare or navigation devices.

M2M SIM Functionality

There are three IoT SIM models:

  • Standard IoT SIMs are designed for IoT but built on the backbone of traditional SIM technology. You’ll get the features you need to keep your IoT devices connected and manageable without the extra overhead of durability. These work well for IoT devices in simple, less harsh environments.
  • Industrial IoT SIMs are much more durable and designed to survive extreme conditions. They’re resistant to high and low temperatures, vibrations, corrosion, and more.
  • Automotive IoT SIMs are similar to industrial IoT SIMs but built explicitly for connected motor vehicles. These are resistant to more extreme temperatures, the weather, vibrations, and motion that go along with moving vehicles.

M2M SIM Security

Like anything else connected to a publicly accessible network, IoT devices are vulnerable to hacking or tampering. Two key strategies for keeping IoT networks secure are VPNs and APNs.


APN stands for Access Point Name. It acts as a middle man between a particular network and the devices trying to connect to it, adding a layer of security to the devices on your network.

Using an APN starts with the right SIM card. Any device that wants to connect to an APN network needs a specially programmed SIM. There is no way for someone to connect to your IoT devices without access to your APN network.

A private APN network means that you’ll only be sharing that network with your other devices, which also helps prevent network congestion.


VPN stands for Virtual Private Network, and you can use it without requiring additional processing power from your device. VPNs encrypt your devices’ connection to the internet, so your device and its data are protected from outside access.

The most secure subset of VPNs is IPsec (Internet Protocol Security). When IoT projects use IPsec VPNs, all data sent through the network is authenticated and encrypted. The IPsec VPN makes sure that the device connected is trusted, that all data being transmitted is safe, and that all data being transferred is encrypted and secure from potential threats.

Where are M2M SIMs in Use?

M2M2M SIMs have endless potential to make devices and entire industries smarter. Popular uses include healthcaretransportation and logistics, and fixed systems and infrastructure. In a rapidly undergoing digital transformation world, M2M SIMs are increasingly utilised.

Visit our M2M SIM case studies page to explore specific uses in the taxi industryvehicle trackingasset trackinghealthcareutilitiesagricultureretail, point of sale, and more.

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How to Get Started with IoT Using M2M SIMs

Jumpstart your connected future by applying for your free trial with Velos IoT’s M2M SIM cards. We offer an all-in-one solution for IoT SIMs, a connectivity management platform, and global m2m networks in 210+ countries and territories. Use our to use our M2M SIM cards in Asia, Africa, North and South America, Australia or Europe.

Velos IoT M2M SIMs are:

  • Non-steered open roaming so you can always connect to the strongest signal available
  • Available in all form factors for any device
  • Available with Fixed IP addresses for reliable access
  • Available with IPsec VPN and APN security protocols to protect data and networks
  • Managed by our Nomad Connectivity Management Platform for deep control and insights on all of your SIM devices

Want to know more? Get in touch.

Whether it is a global IoT deployment or a local project, our connectivity solutions are designed to give you the flexibility to scale your business. Contact us to find out how our experts can help