What Made Data Cheap

For twenty years, the reliable rule of international travel was that using your phone abroad was ruinous and using someone else’s network was awkward. Roaming bills arrived weeks later with numbers that made people switch their handsets off at the border. The local SIM was the answer, and it cost an hour, a passport, a shop queue and a lost phone number. That whole problem has quietly dissolved, and the reason is not generosity.

What changed in the hardware

The embedded SIM removed the physical object. A profile can be provisioned over the air, from anywhere, in minutes, with no counter and no plastic. That single change dropped the cost of acquiring a customer for a foreign data plan almost to zero, and it opened the market to resellers who own no network at all: they buy wholesale capacity from operators, wrap it in an app, and sell it in units of a few gigabytes to travellers who will never be long-term customers.

That last point is the commercially interesting one. A mobile operator’s business is built on retaining subscribers for years; a two-week visitor is worth almost nothing to it and costs almost nothing to serve, since the capacity exists whether or not it is used. Selling that capacity wholesale to an aggregator is close to free money, and the aggregators compete with each other rather than with the operator’s own retail business. The result is a genuinely competitive market in a product that was previously sold by monopoly at the airport.

Regional bundles covering a continent, single-country plans priced for a fortnight, and pay-as-you-go top-ups all compete on the same comparison pages, and the prices have fallen accordingly — in many markets to a small fraction of what a roaming day-pass costs from the same underlying network.

The eSIM did not make data cheap. It made data shoppable, and shoppable is what makes things cheap.

Where the remaining money is hiding

Three places. First, the day-pass from your home carrier, which is priced for convenience and is almost always the most expensive way to get connected — reasonable for a two-day trip, indefensible for two weeks. Second, the airport kiosk, which still sells physical SIMs at a tourist premium to people who did not sort it out beforehand. Third, and less obviously, the regional bundle that looks like good value per gigabyte but covers a set of countries you are not visiting: a single-country plan is frequently cheaper than the regional one that includes it.

There is a fourth, subtler one. Per-gigabyte pricing on travel eSIMs falls sharply with plan size, which makes the large bundle look like the rational purchase — and most travellers use far less data than they buy, because accommodation wifi covers the evening. Buying small and topping up is usually cheaper than buying the bundle that will not run out.

The cost that is not money

A travel eSIM is usually data-only. You keep your home number for calls and messages only if your handset supports two active profiles and you leave the home line on with data roaming disabled on that line — the line itself must still roam to receive anything, and a carrier-level roaming block silences it entirely, which is exactly the failure being warned about here: the bank verification code goes to a phone that is not receiving. That is now the commonest failure in the whole arrangement, and it has nothing to do with price. Anyone whose bank, airline or email uses SMS verification should test the configuration before leaving rather than discovering it at a payment screen abroad.

The second non-monetary cost is support. A reseller with no network has no engineer: when a profile fails to activate on a particular handset in a particular country, the resolution is a chat window and a refund, not a fix. This is a real risk on arrival in a country where you cannot buy a local SIM without registration.

What to actually check

The network the reseller is riding on, because coverage outside cities is a property of the host network and nothing else — a cheap plan on the weakest of three national operators is a bad deal in mountains. Whether the plan includes tethering, which some cheap bundles quietly exclude. Whether unused data expires and when. Whether the country you are entering requires SIM registration against a passport, in which case an eSIM bought abroad may sidestep a requirement that a local SIM would enforce. And whether your handset is carrier-locked, which is the one obstacle no app can route around.

The honest summary is that connectivity has stopped being a travel expense worth planning around in most of the world, and the exceptions are now geographic rather than commercial: places where the network simply is not there, and places where the state has reasons for it not to be. That is a much better problem than a bill.