How to Switch Between SIM Cards and eSIMs on iPhone

To switch between SIM cards and eSIMs on iPhone, open Settings, then tap Mobile Service or Mobile Data in the UK (Cellular in the US). There you can turn each line on or off, choose which line uses mobile data, and set a default line for calls and messages. Menu names can differ slightly between iOS versions and countries.

To switch between SIM cards and eSIMs on iPhone, open Settings, then tap Mobile Service or Mobile Data in the UK (Cellular in the US). There you can turn each line on or off, choose which line uses mobile data, and set a default line for calls and messages. Menu names can differ slightly between iOS versions and countries.

How dual SIM works on iPhone

Recent iPhones can hold more than one line: a physical SIM plus an eSIM, or two eSIMs, depending on model. This means you can keep your home number active while adding a travel eSIM, and switch between them in Settings without removing anything.

Each line works independently. You can have one line for calls and texts and another for mobile data, or turn a line off when you do not need it. Because the lines are separate, you can keep your home SIM available for calls and SMS while a travel eSIM handles data.

To see your lines, open Settings, then tap Mobile Service or Mobile Data in the UK (Cellular in the US). You will see each line listed. From here you can manage everything covered in the sections below.

Choose which line uses mobile data

In Settings, under Mobile Service or Mobile Data in the UK (Cellular in the US), you pick which line is used for mobile data. This is the line your phone uses for internet access when you are not on Wi-Fi.

1. Open Settings.
2. Tap Mobile Service or Mobile Data in the UK (Cellular in the US).
3. Tap Mobile Data.
4. Select the line you want to use for mobile data.

If you are travelling, set your travel eSIM as the mobile data line. That way, apps and browsing use the travel eSIM rather than your home line. You can change this at any time.

Choose your default line for calls and texts

Also in Settings, under Mobile Service or Mobile Data in the UK (Cellular in the US), you set a default line for calls and messages. This is the line used when you make a call or send a text unless you choose otherwise.

1. Open Settings.
2. Tap Mobile Service or Mobile Data in the UK (Cellular in the US).
3. Tap Default Voice Line.
4. Select the line you want as your default for calls and texts.

You can still choose a different line for a specific call or message when you dial or compose. The default line is simply the one used automatically.

Turn a line on or off

Each line can be turned on or off without deleting it. This is useful when you want to stop a line from receiving calls, texts or data without removing the SIM or eSIM.

1. Open Settings.
2. Tap Mobile Service or Mobile Data in the UK (Cellular in the US).
3. Tap the line you want to manage.
4. Turn the line on or off.

Turning a line off does not delete it. You can turn it back on later. This can help you avoid unwanted charges when you are abroad, for example by turning off your home line's data while keeping it on for calls and SMS.

Travel setup: home SIM plus travel eSIM

Typical travel setup: travel eSIM set as the mobile data line with data roaming on for that line; home SIM kept on for calls and SMS with its data roaming off. Mobile Data Switching lets the iPhone use the other line's data when coverage drops; for travel, keep it off so data only uses the travel eSIM.

To set this up:

1. Install your travel eSIM if you have not already.
2. Open Settings, then tap Mobile Service or Mobile Data in the UK (Cellular in the US).
3. Set the travel eSIM as the line for Mobile Data.
4. Turn on data roaming for the travel eSIM line only.
5. Keep your home SIM on for calls and SMS, but turn its data roaming off.
6. Turn off Mobile Data Switching so data only uses the travel eSIM.

This keeps your home number available for calls and texts, including one-time passcodes, while your travel eSIM provides data. For more on how calls, texts and OTPs work on a data eSIM, see calls, texts and OTPs on a data eSIM.

Menu names can differ slightly between iOS versions and countries. If you cannot find a setting, check the names in your phone's settings app.