Every IoT SIM provider claims global coverage. Most quote the same impressive numbers. 190 countries. 600 networks. Worldwide reach.
None of that tells you whether your EV charger in rural Bavaria will stay connected on a Tuesday afternoon when the primary network gets congested. This issue unpacks what "coverage" actually means for IoT reliability, and the three things your provider is not showing you on their coverage map.
Your IoT SIM provider says they cover Germany. Good. But which Germany?
The Germany where your asset tracker works on the autobahn near Munich? Or the Germany where your industrial sensor sits inside a metal cabinet in a factory basement outside Duisburg?
These are different problems. And the number of countries on a coverage map does not distinguish between them.
When enterprises evaluate IoT connectivity, the first question is almost always about coverage. "Do you cover the countries where we deploy?" It feels like the right question. It is not. The right question is: "What happens to my device when the primary network in that location fails?"
That question separates providers who resell airtime from providers who control the infrastructure.
Coverage is a checkbox. Reliability is architecture.
Most IoT SIM providers work through roaming agreements with mobile network operators. Your device gets a SIM, it connects to a network, and everything works. Until it does not.
Single-IMSI SIMs tie your device to one network operator per country. If that operator has an outage, your device goes dark. If signal strength drops inside a building or below ground, your device has no fallback. If the network gets congested during peak hours, your device waits in line behind consumer smartphones.
For a fitness tracker, that is an inconvenience. For an access control system at a water treatment plant, that is a security incident. For a fleet of EV chargers processing payments, that is lost revenue.
The problem is not that your provider lied about coverage. The map is technically correct. They do have an agreement with a network in that country. The problem is that "covered" and "reliably connected" are two different things, and nobody puts the difference on a datasheet.
What multi-IMSI changes (and what it does not)
Multi-IMSI technology loads multiple carrier profiles onto a single SIM. When one network drops, the SIM switches to another. This solves the single-point-of-failure problem and gives your device options in each market.
It is a significant improvement over single-carrier SIMs. But not all multi-IMSI implementations are equal.
Some providers pre-load two or three profiles per region and call it done. The switching logic lives on the SIM applet, and your device firmware handles the failover. When the device switches between profiles, it detaches from one network and reattaches to another. That process takes time. For some devices, it means a connectivity gap of several seconds to over a minute. For latency-sensitive applications, that gap matters.
Other providers manage the switching from the network core. The device keeps a single APN and a consistent connection, while routing decisions happen upstream. No cycling through profiles. No firmware dependencies. No gaps.
The difference is invisible on a coverage map. Both providers show the same countries in green. But the experience your device has in a concrete parking garage in Rotterdam is completely different.
The permanent roaming problem nobody talks about at the sales meeting
Here is something that rarely comes up in initial conversations with IoT SIM providers: permanent roaming restrictions.
When your device connects to a foreign network and stays there for months, that is permanent roaming. Multiple countries now restrict or ban it. Brazil, Turkey, and Nigeria have formal bans. China, India, Saudi Arabia, and the UAE effectively prohibit it through local regulations. Even within Europe, where roaming rules are more relaxed for consumer devices, IoT deployments face a different reality. Operators designed roaming agreements for smartphones on holiday, not for sensors that sit in one location for five years.
Some countries enforce disconnection after 60 to 120 days. No warning. Your device goes offline, and getting it back online means replacing the SIM or renegotiating terms with the local operator. If your provider relies on standard roaming agreements to deliver "global coverage," your devices in these markets are operating on borrowed time.
The alternative is localized connectivity, where your SIM authenticates as a local subscriber on the visited network. This requires your provider to have direct agreements with operators in each market, or to operate as a full MVNO with control over how SIMs are provisioned and authenticated.
Ask your provider: "Are my devices permanently roaming in the markets where they are deployed?" If the answer is unclear, your coverage map has an expiration date.
Three questions worth asking before you sign
If you are evaluating IoT SIM providers, or reviewing your current setup, these three questions reveal more about reliability than any coverage map:
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"How many carrier profiles does my SIM access per market, and who controls the switching logic?" The answer tells you whether you have genuine redundancy or a single network with a backup that kicks in too late.
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"What happens to my connectivity in markets with permanent roaming restrictions?" The answer tells you whether your provider has localized agreements or is relying on roaming that regulators are actively working to limit.
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"Where does my data go between the device and my cloud platform? Does it route through your core network, or does it traverse the public internet?" The answer tells you whether your provider controls the data path or whether you are one carrier policy change away from a routing surprise.
These are not trick questions. Any provider who controls their own infrastructure will answer them confidently. Providers who resell someone else's network will give you qualified answers full of caveats.
Reliability is not a line item
Coverage maps are marketing tools. They are designed to show you green where competitors show gaps. They do not show you what happens at 3am when a tower goes down, or when a local operator changes its roaming policy, or when your device is deployed in a location where signal penetration requires a fallback carrier.
Reliability comes from architecture. Multi-network redundancy per market. Core network control over routing and policies. Localized connectivity that does not depend on roaming goodwill. Real-time visibility so you know the moment something goes wrong, not 48 hours later.
If your IoT deployment supports operations where downtime has consequences, the question is not "do you have coverage." It is "do you have control."
About IXT
IXT is a full MVNO built for IoT. We deliver global connectivity through a single SIM with multi-IMSI access to 600+ networks across 190+ countries. As a full MVNO, we control our own core network, which means we control routing, policies, and security for every device. Our CMP provides real-time visibility into device status, data usage, and network events, not batched data from yesterday. Whether you run 500 devices or 50,000, IXT gives you connectivity you do not have to think about.
Want to test it? Request a free test SIM at ixt.io.
FAQ section
What is the difference between IoT coverage and IoT connectivity reliability?
Coverage refers to the geographic footprint where a SIM provider has roaming agreements or network access. Reliability refers to the ability to maintain a consistent connection in real-world conditions, including network outages, signal degradation, congestion, and regulatory restrictions. A provider with broad coverage does not automatically deliver reliable connectivity. Reliability depends on architecture: multi-network access per market, core network control, and localized connectivity that avoids permanent roaming restrictions.
Why do single-IMSI IoT SIMs fail in the field?
Single-IMSI SIMs connect to one network operator per country. If that operator experiences an outage, congestion, or reduced signal in a specific location, the device has no fallback option. For IoT deployments in buildings, basements, industrial sites, or rural areas where signal conditions vary, a single network dependency creates a reliability risk that coverage maps do not reflect.
What are permanent roaming restrictions for IoT devices?
Permanent roaming occurs when an IoT device connects to a foreign network and remains there indefinitely. Several countries restrict or ban this practice, including Brazil, Turkey, Nigeria, China, India, Saudi Arabia, and the UAE. Devices using standard roaming agreements in these markets risk disconnection after 60 to 120 days. Providers with localized connectivity agreements or full MVNO status mitigate this risk by authenticating devices as local subscribers.
How does multi-IMSI improve IoT device reliability?
Multi-IMSI SIMs carry multiple carrier profiles, allowing the device to switch to an alternative network when the primary connection fails. This provides redundancy within each market. The implementation matters: some solutions manage switching on the SIM applet with gaps during failover, while others route switching through the network core for seamless transitions. The number of available profiles per market and who controls the switching logic determines actual reliability improvement.
What should I ask my IoT SIM provider about reliability?
Three questions reveal the most about reliability: First, how many carrier profiles does the SIM access per market, and where does the switching logic run? Second, how does the provider handle permanent roaming restrictions in target deployment markets? Third, does data route through the provider's own core network, or does it traverse the public internet? Providers who operate as full MVNOs with direct network agreements will answer these questions with specifics rather than qualifications.
