What Is an eSIM? How eSIMs Work for IoT Deployments

Service disruptions, coverage gaps, and network shifts can quickly render an initial carrier choice ineffective, yet swapping physical SIM cards incurs expensive field support. By utilizing an eSIM, OEMs and enterprises can update carrier profiles over the air. However, the effectiveness of this technology relies on available profile options, hardware capabilities, and failover mechanisms during network drops.

This blog post explores the mechanics of IoT eSIMs, the role of SGP.32, and key evaluation criteria prior to deployment.

What is an eSIM?

An eSIM is a SIM that uses eUICC (embedded Universal Integrated Circuit Card) technology to securely store multiple carrier profiles and allow those profiles to be provisioned and managed remotely. Supported management systems can download, install, enable, disable and delete profiles on the eUICC, so your team can change a device's active carrier profile without touching the SIM.

The technology is well past the early-adopter stage. The Trusted Connectivity Alliance estimates that 605 million eSIMs shipped worldwide in 2025, up 18% on the year before, across consumer and IoT devices combined.

For IoT deployments, remote profile management supports carrier profile changes after installation and fleet-wide profile operations. Supported functions vary by implementation, including the ability to manage devices in groups and recover from interrupted or unsuccessful profile changes. These capabilities are key considerations when evaluating an eSIM provider.

What is a carrier profile?

A carrier profile contains the subscriber credentials and related information a device needs to authenticate with a cellular network. On a traditional SIM, that profile stays tied to one carrier for the life of the card.

An eUICC can store multiple carrier profiles and switch which profile is enabled. In a typical single-active-profile IoT implementation, one profile is enabled at a time. Profile changes can be initiated remotely through a supported management system or triggered automatically by configured switching rules.

Does an eSIM have to be embedded?

No. An eSIM can be soldered into a device as an MFF2 component or supplied as a removable card, such as a Tri-Cut SIM that fits 2FF, 3FF and 4FF slots. "Embedded" describes how a component is installed, while eUICC describes its profile-management capability.

A soldered SIM does not automatically support remote provisioning. An embedded SIM can just as easily be a traditional UICC fixed to a single carrier profile, packaged in a smaller and more durable format. When you evaluate a SIM strategy, keep the physical decisions apart from the capability decisions:

Learn more: SIM Card Types and Sizes Explained

How do eSIMs work for IoT?

IoT eSIMs follow a profile lifecycle that is managed remotely, without a person at the device. At a basic level, the process looks like this:

1. The device connects to a cellular network using its enabled carrier profile.
2. A supported management system coordinates the required profile operation.
3. An alternative profile is either downloaded to the eUICC or selected from profiles already installed.
4. The device reconnects through the newly enabled profile.

The third step covers two very different operations. Downloading a new profile requires a working communications path, because the profile has to travel over a network to reach the device. Switching to a profile that is already installed does not depend on that download. A device that has lost its only connection cannot fetch a replacement, so the profiles stored on the SIM before an outage largely determine how it can recover.

Consider an enterprise installing cellular gateways at several facilities. Before rollout, the team should decide which profiles each SIM will carry, how each site will be activated, and how a gateway will reconnect if its initial carrier becomes unavailable.

Where does SGP.32 fit?

GSMA has published separate remote provisioning approaches for different device categories, and the one a SIM follows decides who controls profile changes:

SGP.32 is GSMA's eSIM IoT specification. The current version, SGP.32 v1.3, was published in May 2026 (GSMA). It covers remote provisioning and management of the eUICC in IoT devices that are network constrained, user interface constrained, or both. It builds on existing eSIM infrastructure and adds two components:

• eSIM IoT Remote Manager (eIM): Coordinates remote profile operations, including triggering downloads and enabling, disabling or deleting profiles, for a single device or an entire fleet.
• IoT Profile Assistant (IPA): Carries out those operations on the device side. It can reside in the device's firmware (IPAd) or directly in the eUICC (IPAe). An IPAe keeps that logic on the SIM, which can reduce the integration work your device team takes on.

With this architecture, profile management becomes practical for equipment that cannot rely on someone scanning a QR code or tapping through an activation screen. It is also arriving as IoT fleets scale. Juniper Research expects eSIM-enabled devices to grow from 1.2 billion in 2025 to 1.5 billion in 2026, with connected logistics, oil and gas, and smart street lighting among the fastest-growing IoT sectors as SGP.32 gains traction.

When a provider says it supports SGP.32, treat that as the start of a specific implementation discussion. You still need to determine which components it supplies, which functions and versions it supports, and what integration your device needs.

Learn more: What is GSMA SGP.32 for eSIMs?

What are the benefits of eSIMs for IoT?

eSIMs give IoT deployments greater flexibility to manage connectivity from manufacturing through ongoing operation. Remote profile management can reduce physical SIM replacements, simplify carrier-specific inventory and support changes in network requirements after installation. These capabilities are available in both removable and embedded form factors, subject to compatible hardware and supported carrier services.

Change carrier profiles without replacing the SIM

Remote profile management gives your team an alternative to retrieving devices or dispatching technicians for carrier-related SIM changes. Distributed, sealed, and hard-to-reach equipment benefit enormously from this hands-off approach to connectivity.

It also provides IOT innovators with flexibility. For example, a product rollout may start with a handful of accessible pilot sites but later get the opportunity to expand to equipment installed inside customer buildings and on remote agricultural land. eSIMs leverage carrier and connectivity diversity to allow for stable, predictable coverage across devices, regardless of location.

Simplify SIM inventory and deployment

Every carrier-specific SIM variant adds friction to purchasing, manufacturing, and installation workflows. Teams have to source the right stock, associate it with the correct build, and ship it to the intended location.

An eSIM solution can reduce that variation where the required profiles and device capabilities are supported. It also gives deployment teams more room to make carrier decisions after manufacturing, which helps when you do not know a device's final destination at production. Your hardware still has to be qualified for its intended markets.

Choose a form factor that fits the device

Since eUICC capability functions independently of the physical form factor, hardware designers can select the design that best fits their specific product constraints. Removable eUICCs work well for routers or gateways featuring standard SIM slots, whereas embedded MFF2 chips are optimal for space-constrained wearables, sealed devices, or drones subjected to ongoing vibration.

Although space savings and enhanced durability are specific to the embedded format, eUICC functionality itself can be deployed in either form factor. Consequently, form factor decisions should be made in tandem with enclosure specifications and service plan requirements. For hardware designed for field repair, plan how technicians will perform connectivity diagnostics; for fully sealed units, establish processes to troubleshoot and resolve issues remotely.

Adapt connectivity throughout the product lifecycle

The connectivity requirements of an IoT device can change throughout its operating life. Expansion into new regions, changes in carrier coverage, revised service requirements, and network outages can all create a need for a different carrier profile after deployment. eSIM remote profile management allows supported profiles to be downloaded and enabled without replacing the SIM, reducing the physical maintenance associated with those changes.

This flexibility is especially valuable for equipment expected to remain in service for years, although available carrier services, hardware compatibility, and certifications still determine which networks the device can use.

Is an eSIM the same as a multi-carrier SIM?

The terms describe different capabilities. Multi-carrier or multi-network describes which networks a connectivity service can use. eSIM describes remote provisioning and management of carrier profiles. A provider offering multi-network connectivity may be using any of these approaches:

• Roaming: The device uses its existing profile to access permitted partner networks through its home carrier's roaming agreements.
• Multi-IMSI: A multi-IMSI SIM stores several subscriber identities and switches between them within the SIM.
• eSIM/eUICC: The solution remotely provisions carrier profiles and enables a different one when needed.

Each approach serves different needs, though a single solution can combine them. An eUICC profile might also support roaming outside its home market, for instance. Ensure that your goals are aligned with your connectivity providers’ connectivity strategy. Different solutions facilitate different use cases, like high-data device demands, ultra-low-battery power-saving features, or minimized latency.

What are the limitations of eSIMs?

eSIM capability is one layer of a deployment. Deployment success also depends on carrier relationships, hardware, and the way the overall solution is designed.

Carrier access still depends on available services and agreements

Remote SIM Provisioning (RSP) does not create a service agreement with a carrier. What matters is which profiles a provider can actually supply, and whether each delivers native access or roaming in your intended markets.

For international deployments, a global coverage claim should translate into a plan for your specific countries and operating patterns, with appropriate services and commercial terms, including how it handles permanent roaming restrictions.

Automatic failover requires a specific recovery design

Storing more than one profile is only part of a recovery design. Effective network redundancy also requires a way to detect the relevant failure and activate a usable alternative. eUICC capability alone does not determine when a switch occurs, which profile is selected or whether the process can run without a connection to a remote management system.

The location of the switching logic and the availability of alternative profiles affect recovery. Downloading a new profile requires a working communications path. A profile already stored on the SIM removes that download requirement, but automatic recovery still depends on logic that can trigger and complete the switch under the outage conditions.

Recovery also extends beyond enabling another profile. The device must register on the alternative network, establish a data connection and restore communication with the application. Testing should measure that full sequence, including how long the service remains unavailable and whether the device returns to its preferred profile after connectivity is restored.

Device hardware and certifications still matter

A profile change cannot add a missing frequency band or turn an LTE modem into a 5G RedCap modem. Carrier flexibility stays bounded by the device's module, its antenna design, and the carrier certifications it holds. Before finalizing your SIM strategy, collaborate with your hardware team to evaluate these factors. Thorough evaluation is particularly critical if you intend to maintain a unified device design across diverse regions or carriers.

Features and plans may differ across networks

Treat required services as acceptance criteria. If your product depends on VoLTE, SMS, a power-saving feature like eDRX, or a high-data plan, get confirmation that each one is supported for every device and carrier combination you plan to use.

A successful data session in the lab only proves that data flows. Verify each service the product depends on before rollout.

Learn more: Solving eSIM Limitations with a Connectivity Partner

When is an eSIM a good fit for your IoT deployment?

An eSIM is worth evaluating when future carrier changes would be difficult to manage physically, or when your deployment needs flexibility beyond its initial network choice. Two scenarios make a useful starting point:

• An OEM planning a distributed product rollout: Count the carrier-specific SIM variants your team expects to maintain. Compare that process with an eSIM approach across manufacturing, activation, and support responsibilities.
• An enterprise supporting installed equipment: Map the locations where a connectivity problem would require a service visit. Decide which incidents remote profile management could address and which would still depend on hardware repair or local troubleshooting.

A small, accessible deployment with stable requirements may have a simpler business case for a traditional SIM. Base the decision on the expected lifecycle of the product, since the most capable option is not always the necessary one.

For a more detailed evaluation across hardware, certification, roaming and post-launch management, work through our eSIM readiness checklist.

Simplify connectivity with Zipit eSIM Integrated

Programmable eSIMs are now a practical option for IoT devices, and their value depends on the profiles and recovery design behind them. Zipit eSIM Integrated combines an eUICC with four certified, pre-loaded native U.S. profiles: two from AT&T and one each from Verizon and T-Mobile. Together, those profiles let a single SIM support the full range of services Zipit offers through these carriers, giving OEMs and enterprises access to all three major U.S. networks without stocking carrier-specific SIM variants.

The SIM is available as a removable Industrial Tri-Cut card (Mini, Micro and Nano) or as an embedded MFF2 chip, so your team can choose the format that fits the device and still keep remote profile management. It supports NB-IoT, LTE-M, LTE Cat 1 bis, 4G LTE, 5G RedCap and 5G, with rate plans from 250KB up to Unlimited and Business Internet/FWA. Native profiles also give devices access to carrier features that roaming often restricts, such as VoLTE and SMS for wearables and security call boxes, or eDRX for longer battery life. Availability depends on the applicable carrier service and deployment requirements.

Profile management uses an eIM and an IPA embedded directly in the SIM (IPAe), following the SGP.32 architecture. Because all four profiles are already stored on the SIM, automatic profile failover in the U.S. is handled within the SIM solution when the primary carrier is unavailable. Recovery doesn't wait on a download over a connection that has already failed, and your product team does not have to write carrier-switching logic into device firmware. For devices deployed outside the U.S., Tier 1 authorized roaming is available.

For day-to-day operations, Zipit eSIM Integrated works with Zipit's multi-carrier connectivity management platform, a single pane of glass for profiles, connectivity policies and plans across carriers. Devices still need compatible hardware and the required carrier certifications to use their intended networks, and our team can help you confirm both before rollout.

You may also like:

• Native Connectivity: The Trend Happening in Markets Around the World
• What Is IoT Device Certification & Why It Matters
• How Does a Multi-Carrier IoT Device Choose a Carrier?
• Zipit eSIM Integrated launch announcement