Understanding multi-carrier SIM offerings starts with the two distinct technical mechanisms — multi-IMSI (multiple network identities on a single SIM) and multi-profile eUICC (multiple full operator profiles on a remotely-provisionable chip) — and the commercial mechanism that drives both: steering of roaming. This page explains multi-carrier SIM offerings — how they work, the multi-IMSI versus multi-profile architecture, the steering-of-roaming layer, the typical use cases (IoT, travel, resilience), and the main vendor categories. The audience is enterprise IoT and mobility procurement teams, product teams designing connected devices, and travel-industry buyers evaluating the multi-carrier SIM market.
Key takeaways
- Multi-carrier SIMs work through two mechanisms: multi-IMSI (multiple network identities) or multi-profile eUICC (multiple operator profiles).
- Multi-IMSI is older, simpler, and dominant in IoT and travel SIMs; multi-profile eUICC follows GSMA SGP.02 or SGP.22 and is dominant in user-interactive eSIM.
- Steering of roaming (SoR) is the commercial layer that drives visited-network selection.
- Use cases: international travel, multi-geography IoT shipping, resilience-led multi-network access.
- Vendor categories: global enterprise/travel-SIM (1GLOBAL, Telna, Transatel), IoT-focused (EMnify, Soracom, 1NCE), operator IoT units, specialist travel brands.
- iSIM follows the same GSMA specifications as eUICC and supports the same multi-profile capability.
Multi-IMSI versus multi-profile eUICC
The two technical mechanisms behind multi-carrier SIM offerings deliver a similar end-user effect but work very differently under the hood. Multi-IMSI stores several International Mobile Subscriber Identities on a single SIM (or single eSIM profile). A SIM application or Java applet on the card switches between the IMSIs based on rules — typically the visited country, the radio access network seen, or commands from the home network. Each IMSI corresponds to a different home network and therefore a different set of roaming agreements and visited-network preferences. Multi-IMSI is well-established (it has been in production use since the 2000s), works on any SIM card form factor (plastic, eUICC, iSIM), and does not require any GSMA SGP.* support.
Multi-profile eUICC stores complete operator profiles on an eUICC chip, where each profile is independently provisioned by a different operator’s Subscription Manager Data Preparation (SM-DP+) server using GSMA SGP.02 (M2M architecture) or SGP.22 (consumer architecture). Switching between profiles is a full profile activation, not a quick application-layer toggle, and is typically driven by user interaction (consumer) or platform-level orchestration (M2M). Multi-profile eUICC is the architecture behind consumer eSIM and is increasingly used for high-value IoT deployments where each operator wants their own profile rather than an MVNO wrapper around multiple operators.
Steering of roaming
Steering of roaming (SoR) is the commercial layer through which home operators control the visited-network selection for their outbound roamers. SoR can be implemented through SIM application logic (the SIM tells the device which networks to prefer), through network signalling messages (the home network rejects registration to non-preferred visited networks and forces the device to retry on the preferred network), or both. For multi-carrier SIMs, SoR is the mechanism that turns the underlying multi-IMSI or multi-profile capability into a delivered commercial product — the visited-network preference list, the IMSI or profile switching rules, and the data-rate or QoS tier selection all get expressed through SoR.
Use cases for multi-carrier SIMs
Multi-carrier SIMs deliver value in three main scenarios. International travel: workforce mobile or consumer travel SIMs roaming across many operator networks at local-network rates. IoT deployments shipping into multiple geographies: a single SIM SKU per device, with the SIM picking the right network in each geography — this avoids per-country SIM SKUs and the supply-chain complexity that comes with them. Resilience-led deployments: multi-network access as the redundancy mechanism for point-of-sale terminals, ATMs, or any deployment where the SIM must work on whichever operator has the best signal in each branch. For single-geography fixed-location workforce mobile, a single-operator contract is usually simpler and cheaper than a multi-carrier SIM product.
- International travel — workforce or consumer travel SIMs.
- Multi-geography IoT shipping — one SIM SKU across multiple countries.
- Resilience — multi-network access for POS, ATM, kiosk deployments.
- Vehicle telematics — cross-border driving requires multi-network behaviour.
- Permanent roaming — some IoT deployments where regulatory positioning matters.
- Backhaul redundancy — multi-network cellular as backup to fixed connectivity.
The vendor landscape
| Vendor category | Examples | Mechanism focus | Best for | Price tier |
|---|---|---|---|---|
| Global enterprise / travel SIM | 1GLOBAL (ex-Truphone), Telna, Transatel (NTT) | Multi-IMSI + multi-profile | Workforce mobile, travel SIMs | Per-user or per-line |
| IoT multi-carrier specialist | EMnify, Soracom, 1NCE, Wireless Logic, KORE, Aeris | Multi-IMSI dominant | Multi-geography IoT | Per-SIM or data-pool |
| Operator IoT B2B unit | Vodafone IoT, Deutsche Telekom IoT, Verizon IoT, AT&T IoT | Operator-led multi-IMSI / multi-profile | Operator-anchored IoT | Per-SIM or data-pool |
| Specialist travel SIM brands | Holafly, Airalo, Maya Mobile | Multi-profile eUICC on wholesale layer | Consumer travel | Per-trip data plan |
| Enterprise roaming and IoT (Droam BV) | Droam | Multi-IMSI roaming and IoT | B2B roaming and IoT | Per-SIM or data-pool |
| Wholesale and platform layer | BICS, Syniverse, Tata Communications, NTT | Wholesale enablement | White-label MVNO and operator IoT | Wholesale agreement |
iSIM and the form-factor dimension
Integrated SIM (iSIM) is a SIM implementation embedded directly into the device’s system-on-chip rather than on a separate eUICC chip. iSIM follows the same GSMA SGP.02 / SGP.22 remote provisioning specifications as eUICC, so all the multi-profile capability available on eUICC is also available on iSIM. iSIM is increasingly adopted in IoT devices because it removes a physical component (lower bill of materials), reduces cost, improves reliability, and reduces device footprint. The multi-carrier SIM mechanism (multi-IMSI or multi-profile) is independent of the form factor — both work on plastic SIM, embedded eUICC, and iSIM. The form-factor choice is driven by device design, not by the multi-carrier mechanism.
Procurement considerations
Procurement evaluation of multi-carrier SIM offerings looks at the network footprint (which operator partners in which countries), the steering-of-roaming behaviour (which visited networks the SIM actually steers to, and at what data rates), the management platform (provisioning, monitoring, billing, APIs), the regulatory and permanent-roaming positioning in target markets, the SIM form-factor support (plastic, eUICC, iSIM), the integration with IoT cloud platforms or MDM tooling, and the commercial model (per-SIM monthly, shared data pool, per-trip, hybrid). For multi-geography IoT in particular the permanent-roaming positioning matters — some countries restrict permanent roaming and require an in-country MVNO or operator profile.
How DROAM News reads it
Multi-carrier SIM offerings are a mature category with a well-understood technical foundation (multi-IMSI and GSMA SGP-architecture eUICC), an active commercial layer (steering of roaming), and a clear vendor landscape across enterprise, IoT, and travel-SIM use cases. The 2026 direction of travel is towards more multi-profile eUICC and iSIM adoption in new IoT designs, continued multi-IMSI dominance in travel-SIM and steered-roaming products, and continued consolidation among the specialist vendors. For procurement teams the recommendation is to evaluate vendors on network footprint, steering behaviour, platform features, and regulatory positioning rather than on the underlying multi-IMSI versus multi-profile mechanism, which is mostly invisible at the end-user level. Editorial disclosure: Droam BV, the publisher of DROAM News, operates in the enterprise roaming and IoT connectivity market — that overlaps directly with this coverage and is handled per our editorial policy. We have flagged Droam BV in the vendor table where relevant.
Related DROAM News pages
- Local & Roaming news — roaming, travel SIMs, eSIM, and steering-of-roaming coverage.
- IoT & M2M news — IoT connectivity, multi-IMSI, eUICC, iSIM, and IoT-platform coverage.
- Editorial policy — how we select stories, disclose commercial overlap, and handle corrections.
Sources and references
Multi-IMSI and eUICC mechanism descriptions are drawn from GSMA SGP.02 and SGP.22 specifications and industry technical literature. Vendor names, ownership, and product positioning evolve; verify against the primary source before procurement decisions.
- GSMA eSIM specifications (SGP.02 M2M, SGP.22 consumer, SGP.32 IoT): gsma.com/esim.
- GSMA steering of roaming guidelines: gsma.com.
- 1GLOBAL: 1global.com.
- Transatel: transatel.com.
- EMnify: emnify.com.
- Soracom: soracom.io.
FAQ
What is a multi-carrier SIM and how does it work?
A multi-carrier SIM is a SIM that can use more than one mobile network operator’s service, either by switching between multiple network identities (multi-IMSI) or by holding multiple operator profiles on an eUICC chip (multi-profile eUICC). The multi-IMSI approach is older and more common in IoT and travel SIMs — the SIM holds several International Mobile Subscriber Identities and steers between them based on home-network rules. The multi-profile eUICC approach uses the GSMA SGP.02 (M2M) or SGP.22 (consumer) specifications to download and switch between operator profiles. Both deliver the same end-user effect: connectivity across more than one operator without changing the physical SIM.
What is the difference between multi-IMSI and multi-profile eUICC?
Multi-IMSI stores several IMSIs on a single SIM (or eSIM profile) and switches between them based on rules in the SIM application; it is operationally simpler, well-established, and works on any SIM card. Multi-profile eUICC stores complete operator profiles (each profile is independently provisioned by a different operator’s SM-DP+ server) on an eUICC chip and switches between them as full profile changes; it requires GSMA SGP.02 or SGP.22 architecture support and adds operational complexity. Multi-IMSI is dominant in IoT and steered roaming; multi-profile eUICC is dominant in user-interactive eSIM deployments where the user or device explicitly chooses a profile.
What is steering of roaming and how does it interact with multi-carrier SIMs?
Steering of roaming (SoR) is the operator practice of guiding a roaming SIM onto preferred visited networks rather than letting the SIM choose freely. SoR is implemented through SIM application logic, network signalling messages, or both, and it is the dominant commercial mechanism through which home operators control the visited-network selection for their outbound roamers. For multi-IMSI SIMs, SoR can switch the active IMSI to favour a different home-operator persona in different geographies, which then drives a different roaming-partner selection. The combination of multi-IMSI and SoR is the mechanism behind most travel-SIM and IoT-SIM products that promise local-network rates in many countries.
Who are the main vendors offering multi-carrier SIM products?
The main vendor categories are: global enterprise mobile and travel-SIM vendors (1GLOBAL — formerly Truphone, Telna, Transatel — owned by NTT, Tata Communications); IoT-focused multi-carrier vendors (EMnify, Soracom, 1NCE, Wireless Logic, KORE Wireless, Aeris); operator B2B units offering multi-IMSI or multi-profile IoT/travel SIMs (Vodafone IoT, Deutsche Telekom IoT, Verizon IoT, AT&T IoT); and specialist travel-SIM brands (Holafly, Airalo) operating on top of one of the above wholesale layers. Droam BV operates in the enterprise roaming and IoT-connectivity space as a vendor in this category.
When should an organisation use a multi-carrier SIM?
Multi-carrier SIMs make sense in three main scenarios: international travel (workforce mobile or consumer travel SIMs) where roaming across many operator networks at local-network rates is the value; IoT deployments that ship into multiple geographies (a single SIM SKU per device, with the SIM picking the right network in each geography); and resilience-led deployments where multi-network access is the redundancy mechanism (e.g. point-of-sale terminals that must work on whichever operator has the best signal in each branch). For single-geography fixed-location workforce mobile, a single-operator contract is usually simpler and cheaper.
What is iSIM and how does it relate to multi-carrier SIMs?
Integrated SIM (iSIM) is a SIM implementation embedded directly into the device’s system-on-chip rather than on a separate eUICC chip; it follows the same GSMA SGP.02/SGP.22 remote provisioning specifications as eUICC, so all the multi-profile eUICC capability is also available on iSIM. iSIM is increasingly adopted in IoT devices because it removes a physical component, reduces cost, and improves reliability. Multi-carrier SIM products (both multi-IMSI and multi-profile) can be delivered on plastic SIM, embedded eUICC, or iSIM — the form factor is independent of the multi-carrier mechanism.