How to activate an eSIM on iPhone.

Before you start.

Installing your Mobile Companion eSIM takes 1 minute. Before you begin, check three things:

• An eSIM-compatible, unlocked iPhone. eSIM works on iPhone XS, iPhone XR and later models, as long as the phone isn’t locked to a network. Check your iPhone model first. If you bought in the Mobile Companion app, it has already checked for you.
• A Wi-Fi connection. The eSIM downloads over the internet, so the easiest place to install it is at home, before you travel.
• Your eSIM details to hand. Straight after purchase, your QR code is ready in your Mobile Companion account, with a one-tap install button and the codes for manual installation. The Mobile Companion app can also guide you through it.

Install your eSIM with the QR code.

There are two quick ways to install it: the one-tap install link, or the QR code. Both give you the same eSIM.

The quickest: the one-tap install link

1. 1

   Open your account on the iPhone

   Log in to your Mobile Companion account on the iPhone you’re setting up, then open your eSIM.

2. 2

   Tap Install on iPhone

   It opens the installation straight in Settings. This works with iOS 17.4 or later.

3. 3

   Allow and continue

   When Activate New eSIM appears, tap Allow, then Continue, and follow the steps on screen.

With the QR code

Show the QR code on another screen (a computer or a tablet) or print it: your iPhone can’t scan its own screen.

1. 1

   Open Settings

   Go to Settings > Mobile Service (Mobile Data on older versions of iOS).

2. 2

   Add the eSIM

   Tap Add eSIM, then Use QR Code. You may need to tap Other Options first.

3. 3

   Scan the code

   Point your iPhone at the QR code: it recognises it by itself.

4. 4

   Confirm

   Tap Continue, then Add Mobile Plan, and let the eSIM download. It only takes a few seconds.

Install it without a QR code.

Scan not working? You can type the details in by hand. You need two codes from your Mobile Companion account: the SM-DP+ address and the activation code. Can’t find them? Message support on WhatsApp.

1. 1

   Open the scan screen

   Settings > Mobile Service > Add eSIM > Use QR Code.

2. 2

   Switch to manual entry

   Tap Enter Details Manually at the bottom of the screen.

3. 3

   Paste the codes

   Copy and paste the SM-DP+ address and the activation code, with no extra spaces, then confirm.

Set up your lines: UK SIM and travel eSIM.

Your iPhone now has two lines: your UK SIM (physical or eSIM), which keeps your number, and the Mobile Companion eSIM, which is data-only and has no phone number. Right after the installation, your iPhone asks a few questions:

Label your lines

Give the eSIM a clear name, such as “Travel” or “Japan”, so you can spot it easily in Settings. To change it later: Settings > Mobile Service, tap the line, then Mobile Plan Label.

Choose the line for mobile data

• Default line: your UK line. It keeps your number for calls and texts.
• Mobile data: the eSIM. If you still need mobile internet at home before you leave, keep your UK line for now and switch to the eSIM on departure day or when you land.
• Allow Mobile Data Switching: off. Otherwise your iPhone may switch back to your UK line when the signal drops.

You can change these choices at any time in Settings > Mobile Service > Mobile Data.

Data roaming

There’s nothing to switch on for the eSIM: Mobile Companion is a Japanese line, so it isn’t roaming in Japan. On your UK line, on the other hand, turn data roaming off to avoid charges abroad: Settings > Mobile Service, tap your UK line, then turn off Data Roaming.

iMessage and FaceTime

If your iPhone asks which line to use for iMessage and FaceTime, keep your UK line. They carry on with your usual number and use the eSIM’s data. WhatsApp doesn’t change either: your account stays linked to your UK number.

Which iPhones have eSIM, and what changes.

The steps are the same on every eSIM-compatible iPhone. What changes is mostly the model and the version of iOS:

• iPhone XS, iPhone XR and later support eSIM. On iPhone 14 and later, some models have no SIM tray and use eSIM only.
• iPhone 13 and later can keep two eSIMs active at once. Handy if your UK line is already an eSIM.
• iOS 17.4 or later lets you install from a link with one tap, or by pressing and holding a QR code on the iPhone itself.
• The menu name depends on your version: Mobile Service on recent versions of iOS, Mobile Data on older ones.
• iOS 26 and later may show a Turn On Travel eSIM notification when you land. To keep receiving calls and texts on your UK number, choose to keep both lines: the travel eSIM is then used for data.

Steps checked in October 2026 on Apple’s UK help pages: setting up an eSIM, using Dual SIM and travelling with an eSIM. Labels can vary slightly with your version of iOS.

When you land in Japan.

Turn off aeroplane mode as soon as you land: the eSIM finds the NTT docomo network by itself, in 5G where your iPhone and the network support it. Check that it’s your mobile data line, and you’re online. Your plan starts at this first connection. The arrival steps in detail: switching your eSIM on when you land.

If the eSIM won’t activate.

Check that aeroplane mode is off, that the eSIM line is on (Settings > Mobile Service, tap the line, Turn On This Line) and chosen for mobile data, then restart your iPhone. QR code already used? Don’t keep retrying: it generally works only once. Every fix is in what to do if your eSIM won’t activate, and a real person answers on WhatsApp, 24/7, in English or French.

Back home, you can remove it after your trip or simply turn it off. Don’t have yours yet? Pick a Japan eSIM plan.

FAQ.