Yes – if your hardware supports eUICC and your current connectivity provider has an RSP (Remote SIM Provisioning) platform with accessible APIs. In that case, you can switch operator profiles over the air without touching the device.

If your devices use standard removable SIMs, or even soldered MFF2 SIMs without eUICC software, you cannot switch remotely. You need physical access to the device to swap the SIM. For large UK deployments, this is often the most expensive and operationally complex part of a migration project.

They are related but different things. eUICC (Embedded Universal Integrated Circuit Card) is the GSMA-defined software standard that allows a SIM to store and manage multiple operator profiles and switch between them over-the-air. It is the capability that enables remote switching.

eSIM in marketing usually means a soldered or embedded SIM chip (MFF2 form factor). Confusingly, a chip can be labelled “eSIM” in hardware terms but have no eUICC software on it – meaning it is still locked to one operator and cannot be remotely provisioned.

For IoT, what you need is an eUICC-capable device connected to an RSP platform. The form factor (soldered vs removable) matters less than the software capability and provisioning access. See the full eUICC guide on eUICC.co.uk for a deeper breakdown.

No. This is one of the most common and costly misunderstandings in IoT procurement. “eSIM” as a label does not guarantee portability.

Portability depends on three things: whether the SIM has eUICC software (not just a soldered chip), whether you have access to the RSP platform to manage profile downloads and switches, and whether your commercial agreement with the provider allows you to move profiles to a different platform or operator.

Some providers have “freedom to switch” messaging in their marketing but retain control of the RSP platform and profile entitlements. Before signing, ask explicitly: can I move my profiles to a third-party RSP platform, and what are the commercial and technical steps to do so?

Permanent roaming is when a device lives long-term on a visited network using a foreign IMSI – effectively pretending to be a traveller that never leaves. Many UK IoT deployments have operated this way, using MVNO SIMs with IMSIs from non-UK operators roaming onto UK networks.

The risk is that UK operators can enforce their own policies on long-term roaming devices. Unlike the EU (which has roaming portability rules), the UK post-Brexit does not have the same regulatory framework. This means operators can – and in some cases do – restrict or disconnect long-term roaming devices at their discretion.

The solution is to use a provider that offers local UK IMSI allocation, or an eUICC-based approach that can provision a local profile to meet UK network requirements.

If your UK IoT devices are on 3G only, action is urgent. Vodafone, EE, Three, and O2 have all closed their UK 3G networks. Devices that were 3G-only are no longer connecting, or are failing over to 2G if their hardware supports it – and 2G will not be around indefinitely.

Your options are: replace hardware with 4G/LTE-capable devices and SIMs, assess whether existing hardware has dormant 4G capability that was not configured, or in some cases use Cat-M1 or NB-IoT for low-data applications where the device supports it.

A connectivity provider that handles the SIM swap as part of a managed migration service can help with this, but the hardware decision is ultimately yours.

Multi-IMSI means a SIM has more than one operator identity preloaded. It can select between them – sometimes automatically based on coverage or policy – to connect to different operator cores. This improves resilience and can help with permanent roaming issues in some markets.

“Multi-network” is broader marketing language that often encompasses multi-IMSI but sometimes means something different (multi-carrier roaming agreements without separate IMSIs). Always ask what the mechanism is behind the label.

Neither multi-IMSI nor multi-network is the same as eUICC remote provisioning. They are about coverage resilience, not provider portability. You are still dependent on the entity that controls the identity set.

SGP.32 is the GSMA’s eSIM specification designed specifically for IoT – particularly headless, constrained, or low-power devices that cannot use the consumer eSIM provisioning flow (which relies on a user interface and QR codes). It defines how profiles are managed at scale, including zero-touch provisioning for factory and field scenarios.

For new IoT designs in 2025 and beyond, specifying SGP.32-compatible devices and provisioning platforms is the right approach. It is not yet universally supported across all hardware and providers, but it is the direction the industry is heading and major providers are actively building to it.

If your deployment is already live on older hardware, SGP.32 is not immediately relevant to your current switch – but it should influence your next procurement cycle.

In order of frequency: IP dependencies, management access, and operational tooling gaps.

IP dependencies are the most common failure mode. Firewall allowlists, VPN configurations, private APN setups, and backend endpoint assumptions all depend on the current IP architecture. Switching SIM provider often changes IP ranges, APN names, and routing paths. The SIM connects, but applications cannot reach their servers.

Management access breaks when devices relied on a public static IP or a provider-specific VPN tunnel that does not exist with the new provider. If you cannot reach the device remotely, you cannot complete the migration OTA.

Operational tooling – your network operations team’s alerting, monitoring dashboards, and helpdesk workflows may all be tied to the current provider’s CMP (Connectivity Management Platform). Plan the transition of operational tooling as carefully as the SIM migration itself.

Design for portability from day one. That means specifying eUICC-capable hardware with a confirmed RSP platform and API access in the commercial contract. Decouple remote device access from the SIM’s IP address – use a VPN overlay, private management network, or brokered access approach that works regardless of which network the SIM is on.

Insist on documented commercial exit routes in any connectivity contract. Ask: if I want to move to a different RSP platform or operator in 18 months, what is the technical and commercial process? Get that in writing before you sign.

Also consider connectivity portability at the device firmware level. Hardcoding APN names, IP addresses, or provider-specific endpoints into firmware is an anti-pattern that makes every future migration harder.

For UK-only deployments, a UK-rooted MVNO or a direct carrier agreement often makes more sense than a global aggregator. You get a local IMSI (avoiding permanent roaming risk), UK-based support, and typically simpler commercial terms for a single-country estate.

Global aggregators and MVNOs are better suited for deployments that span multiple countries, or where devices move between regions. Their value is the global footprint and multi-carrier resilience, which you are not fully utilising if everything sits in one country.

That said, some UK deployments benefit from a global MVNO even for UK-only sites – particularly if you want multi-network resilience (coverage from multiple UK networks on a single SIM) or are anticipating future international expansion.