How to set up an eSIM on an iPhone

Setting up an eSIM on your iPhone ensures that you can seamlessly switch between two mobile plans whenever you need to. eSIM setup is essential for configuring how your iPhone manages each plan so you can enjoy your temporary travel data plan without triggering roaming charges on your regular data plan.

saily blog author sabina carbajal
Sabina Carbajal

6 min read

How to set up an eSIM on an iPhone

Table of Contents

Set up an eSIM on iPhone: How is it different from installing or activating?

"Setting up," "installing," and "activating" an eSIM are three distinct steps, each with its own meaning. Understanding the difference is key to getting your eSIM working on your iPhone. See the definitions below.

Installing an eSIM on an iPhone

Adding the eSIM profile to your phone.

Setting up an eSIM on an iPhone

Choosing which line to use for calls vs. mobile data.

Activating an eSIM on an iPhone

Turning the line “On” to connect to cell towers.

Step 1: Label your eSIM plan

The first step to setting up your eSIM is creating a unique label for it to keep track of which plan you’d like to keep enabled. To create a label for your eSIM:

  1. Go to “Settings” > “Cellular” or “Mobile service.”

  2. Under “SIMs,” select the eSIM you just installed. 

  3. Tap “Mobile plan label.”

  4. Create a custom label (e.g., “Travel” or “Saily”) to avoid confusing it with your “Primary” mobile plan.  

Step 2: Set up your Default Voice Line

The Default Voice Line is the phone line automatically used by Siri and iMessage for calls and texts with people who aren't in your contacts. If you want to continue using your regular phone number while traveling, set your Default Voice Line to your "Primary" line. Just keep in mind that you might incur roaming charges from your carrier for calls and texts made with your regular phone number unless international calling and texting are included in your mobile plan. 

To set up your Default Voice Line: 

  1. Go to “Settings” > “Cellular” or “Mobile service.” 

  2. Select “Default voice line.” 

  3. Choose the line you’d like to call and text from. 

Step 3: Set up your Cellular Data Line

Selecting the right Cellular Data Line is essential to avoid roaming charges from your carrier. If you've installed a temporary travel eSIM, you'll need to update this setting. Here's how:

  1. Go to “Settings” > "Cellular" or “Mobile service.” 

  2. Tap “Cellular data” or “Mobile data.” 

  3. Select your new “Travel” eSIM. 

Important tip: Make sure to also turn off the "Allow cellular data switching" setting. If it’s left on, your iPhone may automatically switch back to your home SIM for data, which can result in unexpected roaming charges.

Step 4: Configure iMessage and FaceTime

During eSIM setup, Apple will ask which phone lines you want to use for iMessage. Keep your Primary (home) number checked so your iMessage continues to work normally — your blue bubbles will still send and receive using your travel eSIM's cellular data.

Why is my eSIM data not working?

If something isn't working as expected after installing your travel eSIM, one of these common issues may be the cause.

Problem

Solution

No cellular data on your travel eSIM.

Go to “Settings” > “Cellular” or “Mobile service” and confirm that your travel eSIM is set as the Cellular Data Line. Make sure "Allow cellular data switching" is turned off.

Roaming charges appearing unexpectedly.

Check that "Allow cellular data switching" is disabled. Otherwise, your iPhone may be using your home SIM for data.

iMessage won't activate.

Toggle iMessage off and back on in “Settings” > “Messages,” and ensure your Primary (home) number is checked under "Send & receive."

Sending iMessages or SMS from the wrong number.

Go to “Settings” > “Messages” > “Send & receive” and select your preferred line under “Start new conversations from.”

Calls or texts going out on the wrong line.

Review your Default Voice Line setting in “Settings” > “Cellular” or “Mobile service” and set it to your Primary line.

eSIM isn’t showing up after installation.

Restart your iPhone. If the plan still doesn't appear, confirm the eSIM was fully activated through your carrier or travel eSIM provider.

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