What do iPhone eSIM settings actually do?
Your eSIM settings control which of your plans is used for mobile data, calls, and messages. You can set a default line for each, and choose whether a plan is allowed to connect to networks when you're abroad. It's simply about telling your iPhone which plan to use, and for what.
Stuck on how to install an eSIM on your iPhone in the first place? Check out our full guide.
Where to find eSIM settings on your iPhone
To find your iPhone’s eSIM settings:
Go to “Settings.”
Tap “Cellular” or “Mobile service.”
Under “SIMs,” select your eSIM plan.
Please keep in mind that the navigation path may vary depending on which iOS version you have installed.
A step-by-step guide on configuring your iPhone’s eSIM settings
Take a look at the steps below to learn which settings are essential for using your eSIM and avoiding roaming charges while abroad.
Step 1: Choose your Default Voice Line
The Default Voice Line controls which phone number is used for outgoing calls and incoming calls from unknown contacts, as well as SMS messages. We’d advise you to keep your Primary (home) SIM as the Default Voice Line if you’d like to continue using your phone number while traveling, which can especially come in handy for two-factor authentication (2FA).
To set your Default Voice Line:
Go to “Settings.”
Tap “Cellular” or “Mobile service.”
Tap “Default voice line” and select your preferred line.
Step 2: Select your Cellular Data Line
Selecting the right Cellular Data Line is crucial for avoiding sky-high roaming charges while you’re abroad. If you’ve installed a travel eSIM, you’ll want to make sure that you’re using the mobile data from the prepaid eSIM plan and not your home SIM.
To set your Cellular Data Line:
Go to “Settings.”
Tap “Cellular” or “Mobile service.”
Tap “Cellular data” or “Mobile data” and select your travel eSIM.
You’ll also see an option at the bottom called “Allow mobile data switching.” We would advise you to keep this setting off to avoid having your data switch back to your primary SIM and triggering roaming charges.
The golden rule of using the right mobile data plan is that the “Data roaming” setting needs to be on for your travel eSIM, and off for your primary SIM.
Go to “Settings.”
Tap “Cellular” or “Mobile service.”
Under “SIMs,” select your travel eSIM.
Toggle the switch beside “Turn on this line” as well as the one beside “Data roaming.”
Make sure your home SIM is disabled by toggling “Turn on this line” to the off position.
Step 4: Rename your eSIM plan
Renaming your eSIM plan in your iPhone’s settings will help you keep track of which plans to keep on and off without confusion.
To rename your travel eSIM:
Go to “Settings,” then “Cellular” or “Mobile service.”
Under “SIMs,” select your eSIM.
Tap “Cellular plan label” or “Mobile plan label.”
Add a custom label (e.g., “Travel” or “Saily”).
Aside from the Default Voice Line and Cellular Data Line, Apple also allows iPhone users to select which lines they’d like to keep for iMessage and FaceTime.
If you’d like to keep your regular phone number to receive incoming and outgoing FaceTime calls and iMessages, you can do so through the “Messages” and “FaceTime” settings.
Recommended eSIM settings for travel
Here’s a quick breakdown of which eSIM settings you should have enabled to avoid incurring roaming charges abroad:
Default Cellular Line → travel eSIM
Default Voice Line → Primary SIM
Data roaming → ON for your travel eSIM
Cellular data switching → OFF
