What Is an eSIM and How Does It Work in IoT Devices?

An eSIM (electronic SIM card) is a digital network profile that allows IoT devices to connect to mobile networks without the need for a removable SIM card. It’s stored on an eUICC—a smart, rewritable SIM chip—and managed through remote servers such as SM-DP+ and, for IoT deployments, an EIM (eSIM IoT Manager) based on the GSMA SGP.32 specification. In short, eSIM technology lets IoT devices connect, switch carriers, and stay online anywhere—without ever opening the device.

Quick Navigation

• 1. Understanding the Components of an eSIM System
• 2. A Short History of eSIM Standards
• 3. Why eSIM Matters for IoT and M2M Devices
• 4. What It Means When a Cellular Module “Has an eSIM”
• 5. How Simplex Wireless Helps You Through the eSIM Journey
• Takeaway: eSIM Is the New Standard for IoT Connectivity

1. Understanding the Components of an eSIM System

Before diving into how IoT eSIMs work, it helps to understand the key components involved in every eSIM ecosystem.

1.1 eSIM (Electronic Profile or Network Profile)

The eSIM itself is not the chip—it’s the digital identity that represents a mobile operator’s credentials. Think of it as the electronic equivalent of the SIM card you’d normally insert into a phone.

Each eSIM profile contains:

• The Mobile Network Operator (MNO) credentials.
• The network authentication keys.
• The operator policy settings and service parameters.

IoT devices download and activate these eSIM profiles over the air, eliminating the need for physical SIM replacement.

1.2 eUICC (eSIM-enabled Universal Integrated Circuit Card)

The eUICC is the physical chip that stores one or more eSIM profiles. It’s like a small, rewritable hard drive for mobile connectivity.

An eUICC can:

• Store multiple operator profiles at once.
• Securely activate or deactivate profiles as needed.
• Be embedded directly into IoT hardware (MFF2 form factor).

At Simplex Wireless, our IoT SIM cards include eUICC functionality for both testing (plug-in SIMs) and production (embedded MFF2 variants).

1.3 SM-DP+ (Subscription Manager Data Preparation Plus)

The SM-DP+ server—also called DP+—is where eSIM profiles are securely stored. It’s controlled by the eSIM issuer (for example, Simplex Wireless) and delivers profiles to devices when instructed.

The SM-DP+ works hand-in-hand with the eUICC and ensures secure download and installation of eSIM profiles through encrypted communication.

1.4 SGP.32 eSIM for IoT Components

The newest GSMA standard, SGP.32, introduces new IoT-specific elements to make eSIM management simpler for large-scale deployments.

• EIM (eSIM IoT Manager):

The EIM server acts as the central control point for IoT operators or enterprises. It determines which eSIM profiles should be delivered to which devices and when.

• IPA (IoT Profile Assistant):

The IPA is a lightweight client responsible for communication between the device and the EIM. It can exist:

• On the device itself (IPAd), or
• On the eUICC (IPAe).

This flexible architecture allows IoT devices to manage connectivity autonomously without complex firmware updates—a core strength of SGP.32 and a key feature of Simplex Wireless’s xoSIM solution

2. A Short History of eSIM Standards

eSIM technology has evolved over the past decade to serve different markets.

2.1 SGP.02 — eSIM for M2M (Machine-to-Machine)

The original eSIM standard, SGP.02, was designed for automotive and industrial M2M applications. It allowed operators to remotely change connectivity profiles, but it required complex integrations and device cooperation. While effective for connected cars and high-end industrial equipment, it wasn’t easy to scale across diverse IoT devices.

2.2 SGP.22 — eSIM for Consumer Devices

The SGP.22 specification brought eSIM to phones, tablets, and wearables. This is the standard used by smartphones today. Consumers can scan a QR code to activate an eSIM profile.

However, SGP.22 assumes there’s a user interface—something most IoT devices don’t have. That made it unsuitable for large fleets of unattended machines.

2.3 SGP.32 — eSIM for IoT (The Latest and Greatest)

Introduced to address the limitations of the earlier versions, SGP.32 is purpose-built for IoT and M2M. It combines the remote management capabilities of SGP.02 with the simplicity of SGP.22 while removing the need for user interaction.

Key advantages of SGP.32 eSIM for IoT:

• No user interface required.
• Fully automated provisioning and profile switching.
• Compatible with both IPAe (on-SIM) and IPAd (on-device) models.
• Flexible integration using JSON or ASN.1 communication bindings.

This makes it ideal for IoT sectors such as logistics, smart energy, healthcare, and industrial automation.

Learn how Simplex Wireless’s EIM platform implements the SGP.32 framework entirely in-house—offering carrier-grade performance and independence from MNOs or SIM manufacturers.

3. Why eSIM Matters for IoT and M2M Devices

Now that we’ve covered the components and standards, let’s explore why eSIM is so valuable for IoT deployments.

3.1 Simplifies Global Connectivity

eSIM technology removes the need for region-specific SIMs. With one global IoT SIM card, devices can connect to hundreds of networks around the world.

If regulations or coverage require switching to a local carrier, the eSIM profile can be updated remotely—no physical swaps needed.

3.2 Reduces Operational Costs

Traditional SIM management requires technicians to replace cards manually during carrier migrations or contract changes. eSIM eliminates that need, reducing costly truck rolls and downtime.

3.3 Ensures Device Longevity

IoT devices often operate in the field for 5–10 years. eSIMs—especially embedded MFF2 eUICCs—are built for industrial durability and future-proof carrier flexibility.

3.4 Supports Automated Scaling

Large enterprises can activate, suspend, or switch thousands of SIMs programmatically through APIs. For example, a logistics company can activate eSIMs only when new vehicles ship, keeping costs under control.

3.5 Enables Compliance with Regional Rules

Some countries restrict permanent roaming. With eSIM and SGP.32, devices can automatically download local profiles to comply with regulations in regions like Brazil, India, and Turkey.

4. What It Means When a Cellular Module “Has an eSIM”

You might notice that many cellular modules and IoT modems now advertise “eSIM built in.” But that phrase can mean several different things. Let’s unpack them.

4.1 Built-In eUICC

In many cases, “eSIM inside” simply means the module contains an eUICC chip—the physical component capable of storing eSIM profiles.

If that’s the case, you should verify:

• Which eSIM standard it supports (SGP.02, SGP.22, or SGP.32).
• Whether it has a bootstrap profile pre-loaded to provide initial connectivity.

If the module supports SGP.32, you can use solutions like Simplex xoSIM for full over-the-air control and provisioning.

4.2 Proprietary eSIM Commands

Some manufacturers implement custom AT commands or proprietary firmware features that assist with profile downloads and eSIM lifecycle management. These often integrate with a specific operator’s platform and may not be universally compatible.

4.3 LPA or IPA Software on the Modem

Certain modules include an LPA (Local Profile Assistant) or IPA (IoT Profile Assistant) software agent.

• LPA is common in consumer eSIMs for smartphones.
• IPA—either IPAd or IPAe—is part of the SGP.32 IoT architecture, enabling direct or indirect communication with the EIM server for profile management.

If your module includes IPA support, you’re already ready for next-generation IoT eSIM deployments.

At Simplex Wireless, we help customers determine exactly what level of eSIM support their hardware provides—and how to integrate it with our EIM platform for full automation.

5. How Simplex Wireless Helps You Through the eSIM Journey

eSIM for IoT can feel complex at first, but it doesn’t have to be. At Simplex Wireless, we simplify every step of the process.

Independent eSIM Provider

We’re not tied to any MNO (mobile network operator) or SIM manufacturer (EUM). That independence means you can use Simplex connectivity—or bring your own—and still manage everything through one system.

In-House EIM Platform

Our EIM (eSIM IoT Manager) was built entirely in-house in Atlanta, Georgia by a team with over 30 years of carrier-grade software experience. It supports both Direct and Indirect downloads, ASN.1 and JSON bindings, and is fully compatible with SGP.32.

xoSIM (Open SIM)

Our flagship xoSIM solution offers true flexibility—use Simplex connectivity, your own operator, or a mix of both. xoSIM enables over-the-air subscription switching without truck rolls or device recalls.

Global IoT Connectivity

Simplex provides global IoT SIM cards with access to 191 countries and 550+ networks—all under one unified APN and management interface.

Local Support

All sales, support, and fulfillment are managed locally from our Atlanta headquarters, ensuring quick responses and hands-on assistance for customers across North America.

When in doubt about your module’s eSIM capabilities or your project’s architecture, just talk with Simplex—we’ll guide you through your eSIM journey step by step.

Takeaway: eSIM Is the New Standard for IoT Connectivity

The world of IoT is moving fast, and physical SIM swaps simply can’t keep up. eSIM technology—powered by SGP.32—is the foundation for scalable, cost-efficient, and future-proof IoT connectivity.

To recap:

• The eSIM is the network profile containing carrier credentials.
• The eUICC is the chip that stores and manages those profiles.
• The SM-DP+ server delivers them securely.
• The EIM and IPA components (in SGP.32) make IoT-specific management seamless.
• eSIM enables global scalability, remote provisioning, and total flexibility.

Whether you’re deploying 10 devices or 10,000, eSIM ensures your IoT fleet stays connected—no matter where in the world it operates.

Ready to explore your IoT eSIM strategy? Contact Simplex Wireless or request a trial SIM today.

This article was created by Jan Lattunen, CCO Simplex Wireless

About the Author: Jan Lattunen manages Sales and Marketing for Simplex Wireless. Jan has 20+ years’ experience in working with SIM card technology and was involved in launching the eSIM in North America with major carriers and OEMs. His expertise in telecommunications is around SIM cards. You can connect with Jan on https://linkedin.com/in/JanLattunen or send us an email as sales@simplexwireless.com for more information.