Multi-IMSI eSIM: A comprehensive BICS guide

Staying connected should be simple. But for IoT devices crossing borders, it’s anything but that.

Imagine a logistics truck moving from Germany into Poland, and suddenly its tracking signal drops. Why? The SIM card inside relies on a single network provider, and now it’s out of reach.

These kinds of connectivity gaps are a major hurdle for global IoT deployments from fleet tracking and medical wearables to smart city infrastructure. 

Traditional SIMs, whether roaming-based or locked to one carrier, often can’t keep up with the need for consistent, affordable, and compliant service across borders.

That’s where multi-IMSI eSIM technology comes in. It combines two powerful innovations:

• Multi-IMSI: a SIM card with multiple mobile network identities (IMSIs) built in, allowing devices to connect to a wide range of carrier networks and roaming agreements.
• eSIM: a reprogrammable SIM embedded in the device, allowing remote management and updates.

Together, they form a multi-IMSI eSIM, which is a future-ready solution for scalable, always-on global IoT connectivity.

In this comprehensive guide, we’ll break down what it is, how it works, why it matters, and how BICS is helping enterprises deploy it at scale with our global IoT eSIM Hub.

• IMSI (International Mobile Subscriber Identity): a unique identifier used to connect a device to a mobile network.
• Multi-IMSI: a SIM that holds multiple IMSIs and can switch between them automatically.
• eSIM: a programmable SIM embedded in the device that allows remote updates.

Together, they are a multi-IMSI eSIM– a single, embedded SIM that can switch between networks instantly and be updated remotely.

A multi-IMSI SIM card is a powerful leap over traditional SIMs, where it embeds two or more pre-loaded IMSI profiles (International Mobile Subscriber Identities) directly into a single physical SIM. 

Instead of being tied to one network operator, it can intelligently switch between different carrier identities, enabling devices to connect using the most suitable local network as they move across regions. 

To understand why this matters, remember that each IMSI comprises key identifiers:

• MCC (Mobile Country Code) for the country,
• MNC (Mobile Network Code) for the operator,
• MSIN (Mobile Subscriber Identification Number) for the subscriber itself.

When you set up multi-IMSI, it allows the SIM to behave like multiple localized identities, delivering seamless connectivity across borders. 

By dynamically connecting to the best local networks, it drives down roaming costs and enables enterprises to benefit from smarter, more flexible pricing models.

Beyond cost savings, multi-IMSI supports next-generation network technologies, including NB-IoT, LTE-M, and 5G, ensuring that IoT devices gain reliable coverage across both traditional mobile networks and low-power wide-area networks. 

This combination of optimized costs and expanded coverage makes multi-IMSI a future-ready solution for the global IoT market.

An eSIM (embedded SIM) is a programmable SIM built directly into a device, allowing profiles to be downloaded and managed remotely without the need to physically swap cards. 

While eSIM provides flexibility, combining it with multi-IMSI creates an even stronger model, known as a multi-IMSI eSIM. 

In this approach, a single eSIM can store multiple IMSIs, enabling instant local switching while still supporting remote profile provisioning. 

Enterprises get the best of both worlds, which is the resilience and cost optimization of multi-IMSI together with the adaptability and scalability of eSIM.

• Not multi-SIM phones: Dual SIM slots allow a device to use two physical SIM cards, but they don’t provide automatic network switching.
• Not eSIM profile downloads: eSIMs require new profiles to be downloaded and managed over the air, which can be slower and more complex than instant multi-IMSI switching.

The above visualisation shows how an eSIM profile integrates with multiple IMSIs stored within the same SIM card, each corresponding to a different network partner. 

When a device connects, the SIM server automatically selects the most suitable IMSI for that location. 

This seamless interaction between the eSIM’s remote provisioning capability and the multi-IMSI logic enables instant local connectivity without needing to download new profiles over the air.

A multi-IMSI SIM is designed to manage connectivity intelligently without relying on repeated over-the-air profile downloads. 

Instead of carrying just one operator identity, the SIM comes with a unique multi-IMSI profile that embeds multiple carrier IMSIs. This allows the device to authenticate with the most suitable local network as soon as it powers on.

Each SIM is manufactured with two essential components:

• Bootstrap IMSI to guarantee first-time connectivity when the device is activated.
• Fallback IMSI to ensure service continuity if the active IMSI fails.

The SIM leverages a multi-IMSI applet that manages the logic for selecting and switching IMSIs without requiring manual intervention.

Here’s how the process works:

1. When a device first registers, the SIM automatically contacts a central SIM server, which identifies the best IMSI for the country or region.
2. The selected operational IMSI is pushed to the SIM over the air, giving the device access to local network resources.
3. The SIM continues to check in with the server, which can push new IMSIs if better options become available.
4. If the operational IMSI encounters an issue, the SIM immediately switches to the Fallback IMSI, maintaining uninterrupted service.

This architecture makes a multi-IMSI SIM card far more seamless than traditional roaming solutions and faster than eSIM models that depend on downloading full profiles OTA. 

Enterprises gain a resilient, scalable way to keep devices online wherever they operate.

Multi-IMSI can also be combined with eSIM technology to enhance flexibility. 

In this model, the eSIM provides the remote provisioning capability, while the embedded multi-IMSI profile ensures instant switching between networks without repeated downloads. 

Together, a multi-IMSI eSIM offers enterprises the speed and resilience of automatic local switching, along with the scalability and lifecycle management benefits of eSIM.

To understand how these solutions stack up, here’s a quick comparison of their strengths, limitations, and best-fit scenarios.

Unlike a roaming SIM or local SIM, a multi-IMSI eSIM delivers global reach with built-in local optimization.

Roaming SIMs allow devices to connect abroad, but they depend on roaming agreements that can be costly and unreliable. Network prioritization often favors the home operator, leading to weaker performance internationally. 

For enterprises, this translates into higher costs and unpredictable service quality.

eSIM technology supports multiple profiles, but each new profile must be downloaded and managed remotely. This adds latency, increases operational complexity, and requires more signaling overhead. 

While flexible, it can slow down deployments at scale compared to a multi-IMSI eSIM that switches identities instantly.

Local SIMs offer exceptional connectivity in one country, but they lack scalability. For a global rollout, you would require sourcing and managing separate SIMs in every market. This approach creates operational silos and complicates device lifecycle management.

Integrating a multi-IMSI eSIM card gives the combined strengths of global reach and local optimization. 

It switches identities automatically without the overhead of new profile downloads, avoids the high cost of roaming SIMs, and eliminates the complexity of managing multiple local SIMs. 

For enterprises, it delivers a scalable, cost-efficient, and resilient foundation for global IoT connectivity.

The greatest flexibility comes from combining multi-IMSI with eSIM. A multi-IMSI eSIM, powered by the BICS eSIM Hub, delivers both instant local switching and remote profile provisioning. 

This hybrid approach combines the speed of multi-IMSI with the adaptability of eUICC, giving enterprises maximum flexibility to scale IoT globally, even in regions with permanent roaming restrictions or strict compliance needs.

With multi-IMSI SIM, you can connect IoT devices to the strongest available local network in more than 200 countries. This ensures consistent service across regions and supports all major technologies from 2G to 5G, NB-IoT, and LTE-M. 

Businesses gain truly borderless connectivity without dependence on a single operator.

This is where our multi-IMSI SIM becomes a multi-IMSI eSIM. By pairing it with the BICS eSIM Hub, enterprises gain both instant local switching and remote provisioning. 

A multi-IMSI eSIM is especially valuable for large-scale IoT deployments under GSMA SGP.31/32 standards, for deployments in countries with permanent roaming restrictions, or for industries such as insurance that require global reach with flexible cost and compliance models.

A multi-IMSI eSIM card can hold global bootstrap profiles for first-time activation, global operational profiles for international deployments, and local profiles for in-country optimization. 

Enterprises get the best balance between reach, performance, and cost efficiency.

IoT applications demand always-on connectivity. With built-in fallback IMSIs, a multi-IMSI eSIM card instantly switches when the active IMSI fails. 

This prevents downtime in critical use cases such as healthcare monitoring, fleet tracking, or industrial automation.

Reducing connectivity costs across international operations

Instead of relying solely on roaming agreements, a multi-IMSI solution leverages multiple local IMSIs to minimize charges and eliminate bill shock. Each IMSI can represent a different agreement with one or more networks, giving enterprises the flexibility to choose the most cost-effective option.

Businesses gain predictable pricing and a cost model built to support global IoT expansion without sacrificing profitability.

Simplifying operations with one global SIM strategy

Enterprises no longer need to juggle multiple SKUs, contracts, or manual SIM swaps. With multi-IMSI SIMs, devices automatically connect to the best available network, streamlining supply chains and reducing operational complexity.

This model also ensures regulatory compliance in regions with permanent roaming restrictions, making it a smarter, future-proof solution for long-term IoT scalability.

Multi-IMSI technology enables faster device onboarding compared to downloading new eSIM profiles over the air. When combined with eSIM, it becomes even more powerful. 

A multi-IMSI eSIM not only supports instant local switching but also allows remote lifecycle management at scale. 

This is especially valuable under GSMA SGP.31/32 standards, for global deployments in countries with permanent roaming restrictions, or for industries such as insurance where flexible, compliant, and cost-optimized connectivity is essential.

Businesses benefit from quicker rollouts, easier remote management, and the ability to scale IoT projects without delays.

With 5G standalone, LPWAN, and new eUICC standards on the horizon, enterprises need solutions that can evolve. 

Multi-IMSI is already compatible with these technologies, ensuring that connectivity investments remain secure and ready for the next generation of IoT.

Cross-border fleets often lose connectivity when trucks or containers move outside a home network. Using a multi-IMSI eSIM, transport businesses can now automatically keep vehicles connected to the strongest local carrier. 

Logistics companies gain real-time visibility, reduced downtime, and the ability to optimize routes and delivery schedules without connectivity gaps.

Medical IoT devices such as patient monitors, wearables, or connected diagnostic equipment require constant availability. With a multi-IMSI eSIM card, healthcare providers ensure devices connect to the most reliable local network across regions. 

This improves patient safety, supports remote care models, and avoids service interruptions that could compromise treatment.

Smart city applications such as traffic systems, environmental sensors, and connected utilities depend on continuous, low-latency data flows. When you’re using a multi-IMSI eSIM card, it guarantees that devices can switch to the best available carrier when network conditions change. The city authorities benefit from a reliable infrastructure that supports long-term digital transformation.

Manufacturers building IoT-enabled products for global distribution face challenges with connectivity in different regions. Devices can ship globally with one standard configuration by embedding a multi-IMSI solution at the factory stage.

OEMs reduce production complexity, accelerate go-to-market, and deliver products ready to connect anywhere around the world.

Payment terminals and kiosks need always-on connectivity to process transactions. Through multi-IMSI eSIM, businesses ensure terminals connect through the strongest available network, even if one carrier experiences downtime. 

Benefits like faster checkouts, fewer failed transactions, and improved customer satisfaction become really profitable for retail brands. 

BICS combines technical innovation with global reach, making it one of the most reliable providers of multi-IMSI eSIM card solutions for large-scale IoT. 

• Unique profile with global and local IMSIs: BICS offers a multi-network eSIM that combines global reach with local optimization in a single profile.
• Always-on resilience with bootstrap and fallback: A built-in bootstrap IMSI ensures instant activation, while a fallback IMSI guarantees uninterrupted connectivity.
• Faster switching than OTA eSIM updates: BICS multi-IMSI enables instant network changes, avoiding the delays of single IMSI eSIM profile downloads.
• Real-time SIM server intelligence: The SIM server continuously selects the best IMSI, ensuring devices always connect to the strongest network.
• Offering global coverage with enterprise security: Providing connectivity across 200+ countries, reinforced by IPX and SAFE-grade security for compliance and protection.
• Simplified IoT management: A unified dashboard, layered security, and easy API integration streamline global IoT deployments.

With the BICS eSIM Hub, enterprises get the best of both worlds: the instant switching and cost optimization of multi-IMSI, combined with the flexibility and remote management of eSIM. 

This unique multi-IMSI eSIM capability makes BICS a future-ready partner for global IoT connectivity.

Enterprises cannot afford to let connectivity challenges slow down their IoT ambitions. Multi-IMSI SIM technology ensures that devices connect locally and anywhere in the world, solving the core problems of roaming and reliability.

Leveraging a multi-IMSI eSIM solves the problems of limited coverage, unreliable roaming, and high costs by giving devices the ability to connect locally and securely anywhere in the world.

Multi-IMSI is the foundation for resilient global IoT with built-in fallback, simplified management, and readiness for future technologies.

BICS takes this one step further by combining multi-IMSI eSIM technology with its eSIM Hub, global reach, enterprise-grade security, and unified IoT management tools. 

The result is a solution that makes global deployments faster, simpler, and more cost-efficient.

To see how BICS can help your business scale IoT without borders, explore our Global IoT eSIM Hub.