The sources we use

Sources we use

• Manufacturer specification pages and documentation.
• Technical documentation from the eSIM providers we integrate with.
• Public announcements from local operators in the destination country.
• Government websites for visa, customs and travel rules.
• GSMA standards for the technical definition of eSIM.

Sources we do not use

• Unverifiable forum posts and comments.
• Competitor marketing copy with nothing behind it.
• Speed figures with no stated measurement method.

Why sourcing matters more than it looks

An eSIM is harder to judge before buying than a physical SIM, because you cannot see what you bought until you install it and try it abroad. Every recommendation we publish needs a source that can be traced back, not something the team once heard or assumed. One wrong call can cost a reader an entire trip spent fixing a connection that never worked in the first place.

This page sets out the kinds of sources we rely on, the kinds we refuse, and what happens when two sources disagree, so you can judge for yourself how much weight to give our advice on any given point.

Manufacturer specification pages

For whether a given phone supports eSIM at all, our primary source is the specification page the manufacturer itself publishes, since it is the only party that truly knows which hardware carries an eSIM chip. We cite the official spec page only, not a marketing brochure or a review site that copied a figure from somewhere else without checking it.

The limitation is that a spec page only says the model is capable, not that the particular unit in your hand is unlocked or restricted by the carrier it came from. That is a per-device fact, and no general specification page can answer it for you.

Provider technical documentation

For plans we sell directly, we reference the technical documentation supplied by the provider our system integrates with, since that party defines how a profile behaves, how it renews or tops up, and what limits sit inside the system itself. This documentation answers mechanical questions in more detail than the provider's own marketing page ever does.

What this documentation cannot tell you is network quality in the destination country, since an eSIM provider usually does not own the network itself but connects through a local operator instead. Questions about real-world speed or coverage need a different source to sit alongside it.

Local operator announcements

When we write about the network in a particular country, we reference the local operator's own public announcements — coverage expansions, technology changes, or planned maintenance. These are often published in the local language, so we translate them as closely to the original meaning as we can, without stretching them beyond what the announcement actually says.

The limitation is that an operator's announcement only reflects the moment it was published. Networks in many countries move quickly, both in adding towers and in reprioritising which areas get attention. We always state the date we last checked, so you know how fresh the information is.

Government sources

For visas, customs, and rules around bringing electronic devices into a country, we reference the official website of the relevant government agency or embassy only, not a travel blog or forum that summarises the rule in plain language but cannot be traced back to a primary source.

These rules can change without notice and often depend on the traveller's nationality, so we always note which general case a cited rule applies to, and we recommend checking again with the embassy or agency close to your travel date, especially if your trip has a wrinkle such as dual nationality or a special visa category.

GSMA standards

For the technical definitions behind eSIM itself — what a profile is, how the QR code mechanism works, or how an eUICC differs from a physical SIM — we reference GSMA standards, since GSMA is the body that set the framework manufacturers and providers worldwide build to.

GSMA standards describe the technical mechanism clearly, but they do not say how completely any one provider has implemented them. Real-world implementation still varies by provider, which is why we always reference a provider's own documentation alongside the standard, rather than relying on the standard by itself.

When sources disagree

Sometimes a manufacturer's spec page says a phone supports eSIM, while a provider's own announcement in a particular country says that model is not yet supported for activation on its system. This genuinely happens, and it is not always a mistake by either side — it usually reflects that support depends on both the hardware and the provider's own configuration at the same time.

When this happens, we state both sources on the same page and say plainly that the point is not settled, rather than quietly picking one source without telling you. We do not smooth over a contradiction just to make a page read more tidily, because clarity matters more than a polished-looking paragraph.

Sources for device compatibility

Sources for coverage claims

The phrase nationwide coverage is one we treat carefully. Even when an operator announces countrywide service, remote or mountainous areas can have noticeably weaker signal than cities. We reference the operator's own announcement, and we always qualify it: real coverage depends on the specific area and terrain, not a single figure that applies everywhere in the country.

We do not publish speed figures or coverage percentages of our own measurement, because we have not travelled to test every area of every country we sell plans for. What we can do is say plainly that no such figure exists here, rather than inventing one or borrowing a number from elsewhere to make a page look more authoritative.

What counts as unverifiable

• A forum post or comment claiming a model just works, with no author, date, or exact model stated
• Competitor marketing copy that claims a speed or coverage figure without stating how it was measured
• A speed-test app screenshot with no known location, date, or time of day attached
• A review that never states which handset or which plan the writer actually used

How we date-stamp a source on the page

When we cite an external source, we state the publisher's name and the date we last checked it, so you know whether you are reading something current or something that may already have moved on. Dating a source does not mean it will never change; it means we confirmed it as of that date.

When a source goes stale

An operator changes its rollout plan, a manufacturer discontinues a model, or a government agency adjusts a visa rule — all of this can happen without any notice to us. When we find that an old source no longer matches reality, we correct the affected page and update its date accordingly, rather than leaving an outdated claim sitting on a live page.

Before we cite a new source

1. 1Trace it back to a primary sourceWe look for the original document, not a site that summarised or copied it from somewhere else.
2. 2Confirm who published itWe confirm it is genuinely the manufacturer, provider, or government agency's own site, not a lookalike domain.
3. 3Check the publish and last-edit dateAnything too old is either held back or explicitly flagged as possibly outdated.
4. 4Cross-check a second source where possibleEspecially for device compatibility and travel rules, we try to find a second source that agrees before publishing.
5. 5Record the check date on the pageSo you can see for yourself when this particular fact was last confirmed.

Third-party media and reviews

Like anyone, we come across tech reviews and news articles that mention eSIM. We do not treat them as a primary source for facts about device compatibility or network coverage, though, because a reviewer typically tests with a single unit in a single context, which may not match most of our readers' situations at all.

When a news piece surfaces something interesting, we chase down whatever primary source it cites rather than lifting the quote straight from the article. If we cannot find that underlying source, we leave the claim out of our own pages, however credible the article itself looks.

When no source answers the question at all

Some questions have no confirmed answer from any source at all for a while — whether a brand-new model will actually activate with a given provider, say, before that provider has published its own supported-models list. In that situation we say plainly that nothing is confirmed yet, rather than guessing an answer that sounds more complete than it really is.

If you run into this kind of gap, the fastest route is usually not waiting on us, but contacting the manufacturer or provider directly, since they are the only party who genuinely knows at that point. We update the relevant page as soon as a confirmation appears for others to read later.

Reader conversations are a signal, not a primary source

When several readers report a similar problem through LINE or email within a short span, that pattern is usually a signal for us to go back and check the related page, but we do not use any single reader's message as the sole source for writing a new fact, since each person's experience varies by device model, existing carrier, and the place they were actually using it.

What we do is check with the relevant official source first, then adjust the page if the existing information turns out to be genuinely wrong, rather than editing purely on the strength of an unverified report.

Sources behind the pricing you see

The price shown on a product page comes straight from the provider's own system that we integrate with, not a figure we estimate or guess. When a provider adjusts a price in its system, our product page follows at the next sync. We do not borrow prices from an external comparison site, since those sites usually pull the figure from another layer that may no longer match what the live system actually shows.

If you see a different figure on another site claiming to sell the same plan, the price that actually binds is only the one shown at the moment you check out here, not whatever another site happens to display.

Checklist: spotting a well-sourced page

• It names the publisher, not just says information indicates
• It carries a last-checked date, not only an article publish date
• It says plainly when no verified figure exists, instead of guessing to look complete
• It separates manufacturer fact from the team's own opinion clearly
• It gives you an easy way to report something that looks wrong

Read how we check eSIM information

Check whether your device supports eSIM