Multi-IMSI and eUICC Explained: Resilient Connectivity for IoT

The quick summary: Multi-IMSI and eUICC are two complementary technologies that solve IoT connectivity challenges across borders. Multi-IMSI allows a single SIM to hold multiple network profiles that switch automatically based on location, whilst eUICC (embedded UICC) enables remote provisioning, letting you update or change carrier profiles over-the-air without touching the device. Together, they provide the resilience and flexibility modern IoT deployments need to stay connected, compliant, and secure.

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Multi-IMSI and eUICC technology are two complementary approaches that are reshaping how IoT devices stay connected globally.

 

What is multi-IMSI?

 

Multi-IMSI (International Mobile Subscriber Identity) technology allows a single SIM card to hold multiple network profiles from different mobile operators. Think of it as having several SIM cards in one, each with its own IMSI that can be activated depending on where your device is operating.

 

When a device moves between countries or regions, it can switch to a local IMSI profile rather than relying on roaming. This means your device connects as if it's a local subscriber, not a visitor.

 

Why this matters for IoT

 

Countries like Brazil, Turkey, India and China have introduced strict permanent roaming regulations. These laws require devices to connect via a local network profile after a certain period, often 90 to 180 days. Without multi-IMSI capability, your devices risk being disconnected entirely.

 

Beyond compliance, multi-IMSI delivers tangible operational benefits. Local connectivity typically offers better network priority, improved coverage, and more predictable costs compared to continuous roaming. For deployments in utilities, EV charging, or industrial automation, this translates to better uptime and fewer support tickets.

 

What is eUICC (embedded UICC)?

 

eUICC, often referred to as eSIM technology in the consumer world, takes this concept further. It's a standard developed by the GSMA that enables remote SIM provisioning. This means you can change or update the network profile on a SIM without physically swapping hardware.

 

An eUICC-capable SIM can be reprogrammed over-the-air (OTA) to switch carriers, add new profiles, or update credentials, all whilst the device remains in the field.

 

The power of remote provisioning

 

For IoT deployments, this is transformative. Let's say you're rolling out smart meters across Europe. With traditional SIM cards, you'd need to pre-configure each SIM for a specific carrier before deployment. If network conditions change, or if a carrier's coverage proves inadequate, you're stuck, unless you're willing to send technicians into the field to physically replace SIMs.

 

With eUICC, you can remotely provision a new profile. No site visits. No logistics overhead. No device downtime.

 

This flexibility also future-proofs your deployment. As new carriers emerge or network infrastructure evolves, you're not locked into decisions made at deployment. You maintain control.

 

Multi-IMSI vs eUICC: What's the difference?

 

These technologies solve similar problems but work in different ways.

 

Multi-IMSI is typically pre-loaded with multiple profiles at manufacture. Switching between them can happen automatically based on location or network availability, but adding entirely new profiles later usually isn't possible without eUICC capability.

 

eUICC provides full remote provisioning. You can download new profiles, delete old ones, and reconfigure connectivity entirely—all via secure OTA updates. It's more flexible but requires infrastructure to manage the profile lifecycle.

 

Many modern IoT SIMs combine both. You get the immediate resilience of multi-IMSI for day-one connectivity, plus the long-term adaptability of eUICC for changes down the line.

 

iSIM: The next evolution

 

Whilst we're discussing SIM technology, it's worth mentioning iSIM (integrated SIM). This takes the concept of eSIM further by embedding the SIM functionality directly into the device's chipset, rather than using a separate physical component.

 

iSIM offers the same remote provisioning capabilities as eUICC but with a smaller footprint, lower power consumption, and increased tamper resistance. For space-constrained or security-critical IoT devices, this represents the next step in connectivity evolution.

 

Why this matters for secure IoT deployments

 

At IXT, we don't just see connectivity as a transport layer. When you're deploying devices that handle sensitive data, whether that's payment information from EV chargers, telemetry from smart grids, or operational data from logistics fleets, your connectivity needs to be secure by design.

 

Multi-IMSI and eUICC aren't just about staying connected. They're about maintaining control. With the ability to switch profiles remotely, you can:

 

• Route traffic through private APNs or secure tunnels without hardware changes
• Respond quickly to security incidents by isolating or reconfiguring compromised devices
• Ensure compliance with data residency requirements by switching to local network profiles
• Reduce your attack surface by limiting exposure to shared public networks

 

When combined with Zero Trust architecture, where every connection is authenticated and validated regardless of location, you create a connectivity layer that's resilient, observable, and aligned with regulations like NIS2.

 

Real-world applications

 

EV charging networks: Operators expanding across Europe or other regions need chargers that can connect reliably in each market without managing separate SIM contracts per country. Multi-IMSI ensures chargers connect locally wherever they're deployed, whilst eUICC allows operators to switch providers if coverage proves inadequate or pricing changes, all without site visits to swap SIMs.

 

Utilities and smart metering: With devices deployed for 10+ years, the ability to remotely update network profiles is essential. eUICC means you're not locked into a carrier decision made a decade ago.

 

Industrial automation: Manufacturing sites often span multiple countries. Multi-IMSI provides seamless connectivity across sites, whilst eUICC gives you the flexibility to optimise for cost or performance without production downtime.

 

Logistics and asset tracking: Tracking devices cross borders constantly. Multi-IMSI ensures they maintain connectivity, and eUICC lets you adapt to new routes or regulatory requirements without recalling devices.

 

Getting started with multi-IMSI and eUICC

 

The shift to multi-IMSI and eUICC isn't just about better connectivity, it's about maintaining control as your IoT deployment scales. Whether you're rolling out devices across multiple countries or planning for a decade-long lifecycle, these technologies give you the flexibility to adapt without costly hardware changes or service disruptions.

 

When evaluating providers, look beyond the technical spec sheet. The real value lies in how well the connectivity layer integrates with your security architecture, compliance requirements, and operational workflows. A SIM with multi-IMSI and eUICC capability is only as good as the platform managing it, and the security model protecting it.

 

At IXT, we've built our connectivity platform around this principle: secure by design, flexible by default, and ready for whatever your deployment throws at it.

 

 

FAQ: Multi-IMSI and eUICC for IoT

 

What is the difference between multi-IMSI and eUICC?

 

Multi-IMSI stores multiple carrier profiles on a single SIM card, allowing automatic switching between networks based on location or availability. These profiles are typically pre-loaded at manufacture. eUICC (embedded UICC) goes further by enabling remote provisioning. You can download, update, or delete carrier profiles over-the-air without physical access to the device. Many modern IoT SIMs combine both technologies: multi-IMSI for immediate resilience and eUICC for long-term flexibility.

 

Do I need eUICC if my SIM already has multi-IMSI?

 

It depends on your deployment needs. Multi-IMSI alone works well if your carrier relationships and coverage requirements are stable and known upfront. However, eUICC becomes essential when you need to adapt after deployment, whether that's adding new carrier profiles, responding to network performance issues, or meeting evolving compliance requirements. For long-lifecycle IoT devices (10+ years), eUICC provides crucial future-proofing.

 

How does multi-IMSI help with permanent roaming restrictions?

 

Countries like Brazil, Turkey, India and China restrict how long devices can roam on foreign networks. Typically 90 to 180 days. Multi-IMSI addresses this by storing local carrier profiles that activate when needed, allowing your device to connect as a local subscriber rather than a roaming one. This ensures compliance whilst maintaining connectivity without manual intervention or device recalls.

 

Is eUICC the same as eSIM?

 

eUICC is the technology standard that enables remote SIM provisioning, whilst eSIM refers to the physical form factor; a SIM that's embedded rather than removable. Consumer devices often use the term "eSIM" to describe the entire experience, but technically eUICC is the provisioning standard that can work with both embedded SIMs and traditional removable SIMs. In IoT, you'll often see eUICC capability in various SIM formats including standard SIM cards, eSIMs, and the emerging iSIM (integrated into the chipset).

 

Can eUICC profiles be changed whilst a device is operational?

 

Yes, but implementation varies by provider. Most eUICC solutions allow profile switching with minimal disruption—often just a brief reconnection period. However, critical systems should have failover mechanisms in place. The profile change itself happens over-the-air through secure, encrypted channels. Best practice is to schedule profile updates during maintenance windows for mission-critical deployments, though many modern implementations can switch profiles seamlessly without user-noticeable downtime.

 

 

About the author

IXT writes about IoT connectivity because we build it. We’re a Full-MVNO with our own core network and a CMP we designed in-house, so we see what works at scale and what doesn’t. Our team has decades of experience in M2M/IoT, from network engineering to enterprise rollouts, so the guidance we share is practical, vendor-agnostic and field-tested. Connect, secure and manage devices with confidence using our IoT Connectivity.

IXT – Connected. Secure. Everywhere.