Even though embedded subscriber identity module (eSIM) services have become the default way millions of business travellers connect wirelessly abroad, user experience response times to the same network can differ by a factor of 10 because of decisions made in wholesale agreements they are not aware of, reveals research from Ookla.
The Travel eSIM performance penalty study was based on eSIM performance across 190 destination countries in the second quarter of 2026. It set out to reveal “the hidden” wholesale networks and internet exit points behind more than 50 travel eSIM brands, and how those choices shape latency and speed.
The Speedtest data used in the test captured the SIM profile on the device, the visited network and the point where traffic reaches the public internet. In that way, Ookla said that it was able to map every major travel eSIM brand to the wholesale network that anchors it.
The finding that underlined everything was that travel eSIM was a market coming of age and a supply chain still in the shadows. Among the key trends were that travel eSIMs are taking share of international roaming and not just riding a busier travel year, and that a handful of wholesale networks underpin most of the market. Where an eSIM exits to the internet can also matter as much as the local mobile network, and the study revealed that commercial policy is visible in performance and not just routing.
The study found that measured activity from branded travel eSIMs grew at a double-digit rate in the 12 months to June 2026, substantially outpacing the 12% growth in total international roaming activity and taking travel eSIMs from 2.7% to 3.4% of all measured roaming. Ookla noted that because this share measure is independent of how many people travelled, it points to a genuine shift in traveller behaviour.
In addition, more than 50 retail brands rely on a concentrated pool of providers that orchestrate roaming agreements around the world. Those providers are Hutchison’s networks in Austria and Hong Kong; China Mobile Hong Kong; KPN; Orange; Singtel; Telna; Webbing; Transatel; Proximus; BICS; Plus in Poland; and Sky in the UK. These findings are said to emphasise how brand loyalty does not exist at this layer, with several brands switching wholesale suppliers during the quarter.
From a technology perspective, the study found that under home routing, traffic is sent back through the provider’s core network, often in another country, before reaching the internet and that the result was that true local breakout – where traffic exits in the country being visited – remains uncommon. For example, the data showed that in the same Japanese network, median latency ranged from 54 ms with local routing to 543 ms when traffic was sent through Madrid, despite identical radio conditions.
Download speed distributions revealed caps and throttled plans, with one major brand clustering near 6 Mbps and a free tier near 0.2 Mbps. In the worst brand and destination pairings, latency was up to 30 times higher than for local mobile users on the same network.
Yet ultimately, the survey showed that the commercial momentum behind travel eSIMs is no longer in question. Airalo became the segment’s first unicorn in July 2025 on the back of a $220m round, and the company said it now serves more than 20 million travellers. Holafly, its closest rival, claimed to have crossed $500m in cumulative revenue.
Ookla believes that this addressable base keeps widening as Apple ships eSIM-only iPhones in a growing list of markets and remote SIM provisioning becomes routine across the device base. Distribution is broadening in parallel, from travel platforms embedding connectivity in the booking flow to fintech apps such as Revolut selling data packs beside currency exchange. In the US, T-Mobile now sells its own prepaid travel eSIM for inbound visitors and several national operators quietly white-label wholesale travel eSIM platforms under their own logos.
