Before you buy any travel eSIM, you need two things to be true: your phone has eSIM hardware, and your phone is not locked to a carrier. Most guides only tell you the first one, which is why people still end up with a code they cannot use.
The ten second check
Open your phone dialler and dial:
*#06#
A screen of identifiers appears. Look for a line labelled EID. If it is there, your phone has eSIM hardware.
If you see IMEI numbers and no EID, do not conclude anything yet — check in Settings before you give up. Some Android builds, Chinese-market models among them, return IMEI only from that dial code even on hardware that does support eSIM. On iPhone the reliable place is Settings → General → About, where the EID is listed near the bottom; on Android, look under Settings → About phone. If no EID appears in either place, your phone genuinely cannot use an eSIM, and no plan from anyone will change that.
This works on both iPhone and Android, and it beats checking a compatibility list because it tests the actual device in your hand rather than the model name printed on the box.
The part most guides skip: carrier lock
A phone can have perfectly good eSIM hardware and still refuse a travel eSIM, because the carrier that sold it locked it to their own network.
This catches people out most often when the phone was bought:
- on a monthly instalment plan from a mobile operator,
- second-hand from another country,
- as a subsidised handset bundled with a contract.
If you are unsure, ask your operator directly whether the device is unlocked for use with other networks. Doing that before you travel takes one message. Doing it at the airport takes your whole morning.
Two mistakes that cost money
Installing on arrival. Installing an eSIM needs an internet connection. If you wait until you land, you need Wi-Fi to install the thing that gives you internet. Install at home, then simply switch it on when you arrive.
Deleting it to "start fresh". An eSIM profile can be downloaded once. Delete it, factory reset the phone, or move to a new handset, and it is gone permanently — it cannot be reinstalled, and it cannot be refunded. Treat it like a physical SIM you cannot get a replacement for.
Which phones generally work
As a rule of thumb, eSIM support arrived with the iPhone XS and later, Google Pixel 3 and later, and Samsung Galaxy S20 and later, plus most flagship Android phones since then. Regional variants differ — some Chinese-market models ship without eSIM even when the global version has it — which is exactly why the dial code is the answer rather than a model list.
Once you have checked
If you see an EID and your phone is unlocked, you are ready. Pick your destination, and install the eSIM before you fly.