eSIM downsides and security: an honest take from an eSIM company

We make eSIMs for a living, so you’d expect us to say only nice things. But if you’re searching for “eSIM disadvantages” or “is eSIM safe”, you’ve heard enough nice things and want the other side. So here it is, honestly: eSIM has real limitations, most of them manageable; and on security it’s actually harder to steal than a plastic card, with the real risks sitting somewhere else entirely.

The real downsides, one by one

The first is the hardest one: older phones don’t support it. An eSIM needs a dedicated chip built into the handset, which only became common on mid-range and flagship models from around 2018. No setting will fix an unsupported phone, so before buying any eSIM, confirm your model — see does your phone support eSIM.

The second is easy to overlook: installation needs an internet connection. An eSIM downloads your line’s profile over the network, which sounds obvious until you realise what it implies — you can’t land somewhere with no data and only then start installing. The right move is to install at home over Wi-Fi before you fly, so that on landing the only thing left to do is switch on data roaming. Wait until you’re standing in an arrivals hall with no signal, and you’re first hunting for airport Wi-Fi.

The third is switching phones. Moving an eSIM between devices is clumsier than moving plastic. A physical SIM goes straight into the new handset; an eSIM has to be deleted on the old phone and downloaded again on the new one. iOS now has a built-in transfer flow that works reasonably well, but on Android you usually have to go back to the carrier or seller and get the profile reissued. Details in moving your eSIM to a new phone. Short travel eSIMs expire after the trip anyway, so this mostly matters for long-term lines.

The fourth follows from the third: the QR code you install from generally works once, and binds to one phone. Don’t scan it out of curiosity before you actually mean to install, and don’t assume one code can be shared with a travel companion.

The fifth is about the market rather than the technology: quality among cheap plans is all over the place. The barrier to selling eSIMs is low, so the cheapest offers routinely cut corners on network routing, throttling thresholds, and support — cheap on paper, expensive in practice. That’s a product problem, not an eSIM problem; the breakdown is in the hidden costs of cheap eSIMs.

Is eSIM safe? Start with the counterintuitive part

A common worry goes: if the card becomes invisible data, isn’t it easier to steal? The answer is the opposite. An eSIM is harder to steal than a physical SIM, because there’s nothing to pull out.

A plastic SIM is a physically removable object. If your phone is stolen, the thief can eject the card, drop it into another handset, and your number goes with it — incoming one-time codes and all. An eSIM closes that door: the profile lives on a chip inside the phone, behind the device’s security. As long as the screen is locked, the number can’t be removed or copied out. Against the most common mishap of all, a lost or stolen phone, eSIM is the safer format.

The two risks that actually deserve your attention

Does that mean eSIM has no security story? Not quite — but neither risk lives in the eSIM technology itself.

The first is SIM swap fraud. A scammer impersonates you and talks your carrier into moving your number onto their SIM, then intercepts your text-message codes and works through your bank and accounts. It’s a real threat and worth taking seriously — but the hole is in the carrier’s identity verification, not in the card format. Physical SIM users get hit exactly the same way; switching to eSIM neither exposes you nor protects you. What does help: set a port-out PIN or number lock with your carrier, and move important accounts from SMS codes to an authenticator app.

The second is more mundane: shady low-price sellers. Paying for a QR code that won’t install, “local network” claims that turn out to be rerouted roaming, a support inbox that never answers — all of it happens in the travel eSIM market. Strictly speaking that’s consumer risk rather than a security flaw, but from where you’re standing the result is the same: money spent, no data.

How to spot a provider you can trust

Since the risk mostly lives in who you buy from, choosing the seller is your best protection. A few things you can check before paying.

Is there a real, traceable company behind the product, with proper terms of service and a clear refund policy? Is the pricing transparent, or does the headline number look great while the conditions hide in fine print? And if something breaks at midnight abroad, is there anyone to reach — an actual support channel rather than an inbox that replies in a few days? These sound like low bars. The cheapest plans on the market routinely clear none of them.

They’re also the standards soda set for itself: billing by actual usage; automatically applying the cheapest combination of plans in retrospect at settlement; a balance that never expires; and self-service refunds from the wallet for unused top-ups within the cooling-off period — every number on the table. In the interest of the honesty this article promised, this isn’t a pass for soda: the checklist above works on any provider, ours included.

Who shouldn’t use an eSIM

Honest advice includes when not to bother. Three cases where a physical SIM genuinely serves you better.

If your phone doesn’t support eSIM, that settles it — don’t buy a new phone for the privilege. If you’ll be switching handsets mid-trip, say carrying a backup phone or planning to buy one abroad, the transfer friction will cost you time that a swappable plastic card wouldn’t. And if the user won’t touch settings at all — an elderly parent is the classic case — a physical SIM is a “push it in and it works” object, while an eSIM asks them to scan a code and dig through settings for the roaming toggle. If you won’t be standing next to them, a plastic card plus a note saying “it goes in here” may simply be the kinder setup.

So, is eSIM worth it?

Yes — that’s our position, with two conditions attached. For most phones from 2020 onward and a typical trip abroad, everything on the list above amounts to “one extra step” or “check first” — and in exchange you get online the moment you land, keep your home number live, and can never lose the card. On security, it’s the harder format to steal, and the one threat worth real attention, SIM swap, doesn’t care which format you use.

The conditions: your phone has to support it, and you should buy from a source you trust. The first takes a minute to look up. The second is what the checklist above is for. Clear both, and the downsides of eSIM are manageable — and comfortably outweighed.