An iPhone guide to eSIM that starts in Settings

Which iPhones hold an eSIM, and which do not

Apple introduced eSIM support with the iPhone XS, XS Max and XR generation, and every later iPhone generation has included it. That sentence is accurate and still not sufficient, because regional variants differ. Models sold in mainland China, for example, have historically shipped without eSIM support, and some Hong Kong and Macao variants use a different arrangement again. Two phones with identical names can therefore behave differently.

The reliable test is not the model name but the settings. Open Settings, then Cellular. If the screen offers Add eSIM or Add Cellular Plan, the device supports eSIM. If there is no such entry, it does not, and no amount of provider documentation will change that. Comparing the model number in Settings, General, About with Apple's published list confirms the regional detail.

The second check is carrier lock, and it lives on the same screen. In Settings, General, About, the Carrier Lock entry reads either No SIM restrictions or names a carrier. A locked phone may still accept an installation and then refuse to register on a travel network. If the entry names a carrier, ask that carrier to unlock the device before you buy anything.

• Settings, Cellular: does an Add eSIM option exist?
• Settings, General, About: what does Carrier Lock say?
• Check the model number against Apple's regional compatibility list.
• Remember that recent US models ship without a physical SIM tray.

Adding a travel plan: three paths to the same screen

iOS offers a QR scanner, a manual entry form and, for supported carriers, an app-based installation. All three end with the same confirmation screen showing the plan name and the services included. The differences are practical: the scanner needs a second screen, the manual form needs careful typing, and the app route depends on the provider supporting it.

The QR route begins in Settings, Cellular, Add eSIM, where you choose Use QR Code. Hold the phone steady over the code until the plan details appear. Read the name and the listed services before tapping continue. If the phone reports that the code has already been used, stop and contact the provider rather than scanning repeatedly.

The manual route uses Enter Details Manually on the same screen and asks for a server address and an activation code. Pasting from an email is safer than typing. The app route installs the profile from inside a provider's own app and is generally the smoothest, but it also tends to add more of the provider's own settings, so check afterwards which line became the default for data.

1. Settings, Cellular, Add eSIM.
2. Choose Use QR Code or Enter Details Manually.
3. Confirm the plan details on the summary screen.
4. Label the plan with the provider and trip name.
5. Set the new plan as the mobile data line if it should carry data.

Cellular settings: the two choices that decide routing

iOS separates two questions that sound similar. The first is which line carries mobile data; the second is which line is used for calls and messages by default. A phone can send all its data through a travel eSIM while still placing calls through the home line, and that is usually exactly what a traveller wants.

Mobile Data settings also contains Allow Mobile Data Switching, which permits the phone to use the other line when the preferred one has no coverage. On a trip this can quietly move traffic onto your home tariff, so most travellers switch it off while abroad. Data Roaming is set per line as well and should be enabled only on the line that needs it.

Two further settings are worth a minute. Wi-Fi Calling can keep your home number reachable over a hotel network, if the operator supports it. Low Data Mode reduces background refresh on the travel line, which extends a modest allowance considerably without affecting maps or messaging.

• Mobile Data: set the travel eSIM as the data line.
• Default Voice Line: keep the home line if you need to receive calls and codes.
• Allow Mobile Data Switching: usually off while travelling.
• Data Roaming: on for the travel line if the provider requires it, off for the home line.
• Low Data Mode: a useful default on a small allowance.

Moving a plan to a new iPhone

A travel eSIM installed on one iPhone does not follow you to a replacement device automatically. Apple provides an eSIM Quick Transfer path for supported carriers, which moves a plan between iPhones during setup or from Settings, Cellular. Whether it works depends on the carrier supporting the transfer, and many travel providers do not.

When transfer is unsupported, the provider has to issue a new profile. Some do this free of charge, some charge a fee, and some refuse once a profile has been installed. This is the strongest practical argument for installing a travel eSIM close to departure rather than weeks in advance, and for keeping the order details until the trip ends.

Before selling or trading in an old iPhone, remove the eSIM properly: Settings, Cellular, select the plan, Delete eSIM. Confirm with the provider first that the plan is not needed, because deletion is normally final. Erasing the device without removing the plan can leave the provider believing the profile is still active.

When the iPhone will not connect abroad

Work through the boring checks first. Is the travel plan selected as the mobile data line? Is data roaming enabled for that specific line? Is the phone in a country the plan actually includes? Is airplane mode off? These four questions explain the majority of first-day failures, and none of them requires reinstalling anything.

If the status bar shows Searching or No Service, try selecting a network manually under Settings, Cellular, Network Selection. Choose the partner network named in the provider's documentation if it appears in the list. A carrier settings update may also help: it appears as a prompt, or under Settings, General, About, and it refreshes the operator configuration without touching your data.

What not to do: do not erase the eSIM, do not reset network settings casually, and do not restore the phone from a backup in the hope of fixing a registration problem. Deleting a profile can make a single-use activation code permanently unusable, and a network reset removes saved Wi-Fi passwords without addressing the actual cause.

• Confirm data line, roaming per line, country inclusion and airplane mode.
• Search for networks manually and select a listed partner.
• Check for a carrier settings update.
• Restart the phone once, then retest.
• Contact the provider before deleting the plan.