Travel eSIMs: the blind spot in MNOs’ roaming strategies
What are travel eSIMs?
A travel eSIM allows international travellers to buy data connectivity from alternative roaming providers instead of their home operators, without the need for physical SIM cards. Unlike traditional local SIM cards, travel eSIMs use the consumer eSIM standard. The eSIM is embedded directly into compatible devices and can be remotely loaded with different mobile operators’ profiles.
Before travelling to a country, users typically search among dozens of providers for the best travel eSIM offer. Several comparison websites make this easier.
Once they find an offer, travellers purchase the travel eSIM, which is essentially an IMSI profile. They scan a QR code from their eSIM-capable device. The QR code is an activation code that triggers the load of the purchased IMSI profile onto the device.
Travel eSIM providers have made it incredibly easy for travellers to activate these alternative data plans instantly, at prices significantly lower than roaming charges from home operators.
Behind the scenes, travel eSIM providers have access to multiple IMSI profiles. Each profile may be more suitable for one region than another. It is rare that they use a local IMSI profile; almost always they rely on a roaming profile.
This works by establishing partnerships with IMSI Sponsors who resell their roaming agreements with visited networks. These partnerships may be direct with the MNO IMSI Sponsor, or via an IMSI broker or aggregator with multiple MNO relationships.
Essentially, when a traveller activates a travel eSIM, they are still a roaming subscriber—just from another home operator.
The IMSI Sponsor is the cornerstone of this industry. MNOs with the best wholesale rates and the strongest ability to provide MVNOs with IMSI ranges and consumer eSIM profiles are those best placed to penetrate the market.
Why travellers are switching
Travellers clearly benefit from dramatic cost savings and convenience. Traditional roaming charges can reach $10–15 per day, while travel eSIMs often provide better data packages for $5–20 for an entire trip, with no risk of bill shock. The convenience factor is also significant: no more hunting for local SIM cards at airports or dealing with language barriers in mobile shops.
Mobile network operators face mixed outcomes
For inbound roaming, MNOs often see traffic shift from partners paying higher wholesale IOT rates to partners with cheaper IOT rates. On the other hand, travellers who would otherwise switch roaming off—and generate no revenue—now generate some.
For outbound roaming, some MNOs clearly lose revenue while others gain a share. Retail revenue from traditional roamers disappears for MNOs with high retail prices. Travellers have no problem switching from their home roaming plan to a cheaper alternative. IMSI Sponsors behind the travel eSIM providers benefit from this new revenue stream.
A maze of players
There are dozens of travel eSIM providers. Some source IMSIs directly from IMSI Sponsor MNOs, while others resell through IMSI aggregators.
For the same country, users can end up on the same IMSI Sponsor via different travel eSIM vendors. In other cases, a single travel eSIM vendor may use only one IMSI Sponsor for all destinations.
Figure 1: Partial result of testing eSIMs across vendors, sponsors, and destinations.
A direct consequence of this multiplicity is the disparity in quality between vendors for the same destination.
Internet breakout
Travel eSIMs are still roaming SIMs. The PGW usually sits within the IMSI Sponsor’s home network, or at the MVNO’s data centre if there is one in between. In our tests, some travel eSIMs in Canada broke out in Hong Kong, some in the US broke out in the UK, and all from one vendor broke out in Denmark. These remote breakouts lead to higher latency, sometimes approaching two seconds.
Speedtest results
Speedtest performance depends on the interconnections between the VPMN and the network hosting the PGW. Since PGWs are not always hosted by the native IMSI Sponsor, we observed differences of up to a factor of ten between two speedtests with the same IMSI Sponsor in the same VPMN.
Is it an abuse of agreements?
From an HPMN perspective, there is no abuse: subscribers are free to choose any service provider while abroad.
From a VPMN perspective, however, travel eSIM usage could be interpreted as an abuse of roaming agreements. The definition of “roaming customer” is open to interpretation, and travel eSIM users could be seen as non-legitimate. Regardless, if the VPMN feels abused, it has the right to block users and control access to its network.
What about regulations?
Ultimately, a travel eSIM is still a roaming SIM, so it would fall under the same regulations as a roamer visiting a country.
However, no travel eSIM providers enforce KYC policies. Authorities in visited countries may require KYC for travel eSIM users. Another open question is whether a vendor selling data plans for a specific country is, in effect, an MVNO operating without a licence. I don’t believe so, but I am open to hearing counterarguments.
Regulators will pay more attention—likely pushed by operators citing lost revenue and tax income. Some countries already have regulations in place, such as Turkey and India.
- Turkey: Travel and Tour World article
- India: Times of India article
So what
Undeniably, travel eSIMs are a big step toward cheaper data connectivity while travelling. Quality may be debatable, but for consumer internet traffic, it is usually sufficient.
For home operators, it means lost revenue. The clear response is to communicate and adapt their retail offers. Roaming still suffers from a reputation of being too expensive. (I still hear EU travellers wondering if they should switch off roaming, even though Roam Like at Home has been in place since 2016.) Some operators do have competitive offers, but travellers often don’t bother checking them.
The need for detection
For visited operators, the impact is less clear. But what is clear is that VPMNs need to identify travel eSIM traffic. Travel eSIMs distort the balance between roaming partners. IMSI Sponsors accumulating travel eSIM traffic could become too powerful and gain excessive bargaining power.
VPMNs need visibility to distinguish travel eSIM traffic from legitimate roaming traffic. Detection is essential to evaluate the impact on their networks and revenues.
How to detect
In theory, transparency would be the ideal way to identify travel eSIM sub-IMSI ranges within IMSI Sponsors. They would clearly communicate attributes to help visited networks identify these ranges. No doubt GSMA is working on guidelines for travel eSIM transparency, as it did for IoT. But it’s too late for transparency: too many sub-IMSI ranges have already been sold, by too many providers and aggregators, with inconsistent attributes. IMSIs have already become a non-transparent wholesale commodity.
Transparency will not be enforced by guidelines; only commercial relationships between roaming partners can enforce it.
Market intelligence and expertise
There is still hope. Analytics on the visited network can help operators detect travel eSIMs. Each combination of IMSI Sponsor, IMSI aggregator, and travel eSIM vendor has its own fingerprint and can be identified.
This requires significant market intelligence and signalling expertise. It involves monitoring APNs, signalling inconsistencies, flagged network elements, and other indicators. It is not a one-off job; it requires constant monitoring, pattern recognition, and extensive testing.
That is what we do at Cellusys. As signalling experts, we detect travel eSIMs. Our detection module is available on our Signalling Firewall and Roaming Insight products. Both can identify travel eSIMs and alert your systems with IMSI and IMSI Sponsor HPMN information, enabling action.
Will this become a cat-and-mouse game, with authorised inbound travel eSIMs and unofficial ones, similar to A2P official/grey routes? That depends on the losses for inbound operators and the long-term success of travel eSIMs, which in turn depend on retail roaming rates.
If you’re interested in a demo, don’t hesitate to drop us a line.
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