How to set up an eSIM before you fly (and what to do when it fails)

Setting up a travel eSIM takes about ten minutes at home and one switch after landing. It goes wrong in a few predictable places: a locked phone, a QR code that has already been used, a data line still pointed at the home SIM, and a blank APN. This guide follows the official Apple and Google help pages for the phone side, and the activation and reinstall rules on provider help centers for the plan side. Settings names change between software versions, so if a menu looks different, search the Settings app for the name.

The steps assume a plan you have already bought. To choose one, start with eSIM plans compared. Everything here was read on 2 October 2026.

Two things decide whether an eSIM will work: the phone must support eSIM, and it must not be locked to a single carrier.

On an iPhone, Apple says eSIM is available on the iPhone XS, XS Max and XR and later models, with a different list for phones sold in mainland China. Apple's Dual SIM page has the current list. To check the lock, open Settings, then General, then About, and look for Carrier Lock. "No SIM restrictions" means the phone is unlocked.

Apple's page on unlocking an iPhone for another carrier covers the request. If the phone is locked, start the request days before you fly, not on the night.

On a Pixel, Google says an unlocked device can use eSIM plans from other carriers, and that a phone not bought from your carrier needs the carrier to confirm eSIM support. Google's eSIM carrier page explains this, and its dual SIM page says a Pixel 7 or later can hold two active eSIM profiles if the carrier allows it. For other Android phones, the maker's help pages and your carrier are the source.

Install over a Wi-Fi connection at home or at the departure airport. Apple's instructions ask for a Wi-Fi network or hotspot, and provider help centers say the same: a poor connection can cut a QR scan short, and a half-finished install can leave a code unusable.

Before you install, open the plan's page or confirmation email and look for its activation policy. On most plans the days start counting when the eSIM first connects to a network abroad, so installing at home costs nothing. On a few, the clock starts at installation. One provider also warns that recent iOS versions can combine install and activation, and advises installing only when you are ready to switch the plan on.

You need one of three things from the provider: a QR code, an activation code to type in, or an app that installs the plan for you.

On an iPhone, Apple lists several methods. For a QR code, go to Settings, Cellular, Add eSIM, then Use QR Code, or scan the code with the Camera app and tap the Cellular Plan Detected notification. Enter the confirmation code if the provider gave you one. Apple's page on setting up an eSIM on iPhone has the full set, including entering details by hand.

On a Pixel, open Settings, then Network & internet, then SIMs, then Add SIM, and choose Set up an eSIM, then follow the provider's instructions. Google's page on setting up a new eSIM describes the same path. Your provider's page tells you whether to scan a QR code, type a code or use its app.

Two habits save trouble later. Screenshot the QR code and the activation details, including any APN value, and keep the screenshot on the phone, because you will need them at the moment you have no data. And label the new line with something recognizable. Apple lets you label plans under Settings, Cellular, by tapping the number, then Cellular Plan Label.

An eSIM can be installed and still unused. Only one line at a time carries mobile data, and the phone has to be told which.

On an iPhone, Apple says one number at a time can use cellular data. Open Settings, Cellular, Cellular Data and pick the travel line. Then turn on data roaming for that line: Settings, Cellular, tap the travel number, Cellular Data Options, Data Roaming. Apple's roaming page describes the path. Roaming has to be on for a travel eSIM to connect, even though the plan is prepaid, and provider guides say the same.

Keep the home line on for calls and texts if you need them, with its data roaming switched off. Apple's guide to using an eSIM while traveling warns that a home line left active can still produce roaming fees. If you want to be sure, turn the home line off under Settings, Cellular.

On a Pixel, go to Settings, Network & internet, SIMs. Google says only one SIM can be the default for data, and that Mobile data has to be on for it. The same page lists the Roaming setting, which lets the phone use other carriers' networks when you leave your own carrier's area. Google's mobile network page and dual SIM page cover both. A line you want to stop using can be switched off with Use this SIM.

Leave the travel line off, or its data roaming off, until you land. This is easy to forget, and it matters when a regional plan includes your home country: one provider warns that such a plan can activate at home if it connects there before the trip.

After landing, turn the travel line on, make sure it is the data line, and switch on data roaming for it. Wait for a network name to appear in the status bar. This can take a minute or two, and providers say a restart can help if nothing shows.

The plan clock normally starts here, at first connection, so it is worth confirming that the plan shows as active in the provider's app before you leave the airport. Open a map or a web page and check that data arrives.

A short checklist for the night before you fly:

• The phone is unlocked and updated to the latest software.

• The plan is installed, labeled and switched off, with the QR code and APN saved as screenshots.

• The home line has data roaming off.

• Offline maps are downloaded for the first city.

• The provider's support contact is saved where you can reach it without data.

Most failures fall into four groups. Work through them in order, because the first fixes are the cheapest.

The QR code says it is no longer valid

This message appears when the eSIM has been added before, or when a scan was cut short by a poor connection. It also appears if you removed the eSIM and tried to install it again: one provider's help center says most travel eSIMs cannot be reinstalled once removed.

First check whether the plan is already on the phone. On an iPhone, Settings, General, About lists cellular plans, and an installed eSIM shows as On. If it is not there, switch off any VPN, check the connection, update the software and try another method, such as the manual activation details from the provider's email. Do not delete a plan you still need in order to fix a connection error: one provider's help pages say deleting can invalidate the plan, and another allows up to four installs on the same phone, so rules differ and deletion is a risk. If the code is spent, the provider's support is the way forward, and many can send a replacement through the app or an email.

No signal, or no way to get online to activate

The install needs Wi-Fi, and the plan needs a mobile signal at the destination. If the eSIM shows no network after landing, check four things: the travel line is switched on, it is selected as the data line, data roaming is on for it, and airplane mode is off. Then restart the phone. Provider help pages also suggest selecting the network manually if automatic selection finds nothing, using the network names in the plan instructions. Airport Wi-Fi is enough to open the provider's app and read those instructions.

Signal, but no data

A full signal with nothing loading usually means the data line is wrong or the APN is blank. Check the data line first (Step 3). Then check the APN. On an iPhone, it sits under Settings, Cellular, Cellular Data Network. Apple says iOS 16 and later can fill it in automatically if the carrier supports it, that the field can be edited only if the carrier allows it, and that you should not edit it unless directed by your carrier. Updating iOS resets manual changes. The APN page explains this. Enter the value from the provider's instructions exactly as shown, and leave other fields blank unless told otherwise.

On a Pixel, Google lists Access point names among the mobile network settings, and the provider's instructions give the value to enter.

The hotspot will not work

Tethering depends on both the plan and the phone. Some plans cap or restrict it, and some phones need the APN entered in a separate hotspot field as well. Provider B's help center, for example, describes setting the APN under the personal hotspot entry for the eSIM. If the plan allows tethering and the phone is set up for it, check the same data line and roaming settings as above.

Contact the provider's support first and keep screenshots of the plan, the error and the time. Refund windows are short and differ: 30 days on three of the four providers in the plan comparison, 6 months on the fourth, with conditions on each. One provider asks for faults to be reported within an hour of occurring, and another counts installing the profile as activation. A home-carrier day pass or hotel Wi-Fi covers the gap while a replacement code arrives.

The Japan eSIM roundup has a short section on the same faults in the context of one country.