Quick Answer: Before installing a travel eSIM on your iPhone, connect to a stable Wi-Fi network, then go to Settings → Cellular → Add eSIM. You can scan the QR code provided by your provider or choose to enter the details manually. After installation, set the travel eSIM as your Cellular Data line, turn on Data Roaming as instructed by the product, and prevent your original SIM card from automatically switching to use expensive overseas data. Installing an eSIM doesn't necessarily mean the plan's validity period has started; always refer to the specific product rules in your order.
Installing a travel eSIM usually only takes a few minutes. However, "installed," "activated," and "validity period started" are not always the same thing.
If you don't follow the correct setup sequence, common issues include:
- The eSIM is installed, but you can't connect to the internet upon arriving at your destination.
- Your phone continues to use your original SIM card for mobile data.
- Your primary number incurs unnecessary international roaming charges.
- You mistakenly believe the plan's timer starts the moment it's installed.
- You delete the eSIM during troubleshooting and then cannot reuse the original QR code.
This guide provides a comprehensive walkthrough on how to install, configure, and start using a travel eSIM on an iPhone.
👉 ** Using an Android phone?** Check out How to Install an eSIM on Samsung Galaxy and Google Pixel.
What to Prepare Before Installation
Before you begin, please confirm the following requirements:
1. Your iPhone Supports eSIM
You can check by going to:
Settings → Cellular
And seeing if the following option is available:
Add eSIM
(Note: Apple may use "Mobile Data" instead of "Cellular" depending on your region's language settings.)
You can also go to:
Settings → General → About
And check if an EID is displayed.
If you are still unsure, read our guide first: How to Check If Your Phone Supports eSIM
2. Your iPhone Is Carrier-Unlocked
Go to:
Settings → General → About → Carrier Lock
If it displays:
No SIM restrictions
This generally means your iPhone can use other carriers or travel eSIMs.
If your phone is still locked, even if the hardware supports eSIM, you may not be able to add profiles from other providers.
3. You Have the Correct eSIM Installation Details
Your provider may give you:
- A QR code
- An installation link
- An SM-DP+ Address
- An Activation Code
- A Confirmation Code
- An in-app installation flow
The most common method for travel eSIMs is a QR code. Make sure you are using the exact installation details assigned to your order, and do not scan QR codes found in online articles or other people's orders.
4. Your iPhone Is Connected to a Stable Network
Installing an eSIM requires your iPhone to download a carrier profile from a server. Therefore, you must be connected to a stable Wi-Fi network or an active cellular connection.
Do not start the installation right as you are boarding a plane, in an area with a poor signal, or when your phone battery is extremely low.
5. You Have Read the Plan's Activation Rules
Before installing, check:
- When does the plan start counting down its validity period?
- Can it be installed before departure?
- Does it only activate when you arrive at your destination?
- Do you need to manually configure an APN?
- Do you need to turn on Data Roaming?
- Can the QR code only be installed once?
If the product page or order instructions require you to wait until you arrive to install it, you must follow those specific rules.
Choose a Caylet eSIM for Your Destination
Method 1: Scan a QR Code Displayed on Another Device
This is the most straightforward installation method.
You can open your order email on a computer, tablet, or another phone to display the eSIM QR code, and then use the iPhone you want to install it on to scan the code.
Step 1: Open "Add eSIM"
On your iPhone, go to:
Settings → Cellular → Add eSIM
Depending on your iOS version, the page may also be named:
Set Up Cellular
Step 2: Choose to Use a QR Code
Tap:
Use QR Code
(In some iOS versions, you may need to tap "Other Options" first.)
Step 3: Scan the QR Code
Point your iPhone's camera at the QR code displayed on the other device.
Please ensure:
- The entire QR code is visible.
- There is no severe screen glare.
- You haven't zoomed in so much that the edges are cut off.
- The image isn't blurry or heavily compressed.
- You are definitely scanning the QR code from your own order.
Step 4: Confirm Adding the eSIM
Once your iPhone recognizes the plan, follow the on-screen prompts and tap:
Continue
Then tap:
Add Cellular Plan
If the system asks for a confirmation code, enter the one provided by your eSIM provider.
Wait for the installation to complete. This process can take anywhere from a few seconds to a couple of minutes. Do not close the settings, restart your phone, or disconnect from Wi-Fi during this time.
Method 2: The QR Code Is on the Same iPhone
Many users receive their order email on the exact same iPhone they plan to use the eSIM on, meaning they don't have a second screen to display the QR code.
If your iPhone is running iOS 17.4 or later, and the QR code is displayed in a supported email app or browser, try this:
- Open the email or webpage containing the eSIM QR code.
- Press and hold the QR code image.
- Tap Add eSIM.
- Tap ** Continue**.
- Follow the on-screen instructions to complete the installation.
If pressing and holding does not reveal an "Add eSIM" option, use these alternatives:
- Open the QR code on a computer or tablet.
- Send the QR code to a friend's phone and scan it.
- Use the manual installation details provided by your supplier.
- Check if the order page provides a direct installation link.
Do not upload your QR code to public QR code decoding websites, as this may expose your installation credentials.
Method 3: Scan the QR Code Directly with the Camera App
If the QR code is displayed on another screen or printed on paper, you can also start from the iPhone's default Camera app.
- Point your Camera at the QR code.
- Wait for a "Cellular Plan Detected" notification to appear on the screen.
- Tap the notification.
- Tap ** Continue**.
- Tap ** Add Cellular Plan**.
- Follow the on-screen instructions.
If the Camera app only recognizes it as plain text or a regular website link, switch back to:
Settings → Cellular → Add eSIM → Use QR Code
Method 4: Enter eSIM Details Manually
If the QR code cannot be scanned, or if your provider has given you manual installation details, you can enter them by hand.
Go to:
Settings → Cellular → Add eSIM → Use QR Code
Then tap:
Enter Details Manually
Fill in the fields according to your order:
- ** SM-DP+ Address**
- ** Activation Code**
- ** Confirmation Code** (only if required)
When typing:
- Do not add extra spaces.
- Pay close attention to easily confused letters and numbers.
- Do not paste the entire installation string into a single field.
- Keep your original email handy for double-checking.
- Do not publicly share your full SM-DP+ Address and Activation Code combination.
If your manual details are missing required fields, contact your eSIM provider; do not try to guess them.
After Installation: Label Your eSIM
Once installed, your iPhone may ask you to choose a label for each cellular line.
We recommend naming your travel eSIM something easily recognizable, such as:
Caylet eSIM
Japan Travel
Asia Data
US Data
Travel eSIM
Do not label both your original SIM card and the travel eSIM as "Primary." Doing so makes it easy to accidentally select the wrong data line when you arrive at your destination.
You can change this label at any time by going to:
Settings → Cellular → [Select the Line] → Cellular Plan Label
How to Set Your Default Voice Line?
If your travel eSIM is a data-only plan, it generally lacks traditional phone call and SMS capabilities.
In this case, you should continue to select your original SIM card as the Default Voice Line, allowing your primary number to handle:
- Regular phone calls.
- Traditional SMS texts.
- Your existing iMessage and FaceTime number settings.
- Necessary verification texts (e.g., OTPs).
However, whether your primary number incurs call, SMS, or roaming charges while overseas depends entirely on your home carrier's plan. Keeping the line active does not mean all services are free.
How to Set the Travel eSIM as Your Cellular Data Line?
After installation, the most critical step is designating which line handles your internet access.
Go to:
Settings → Cellular → Cellular Data
Select the travel eSIM you just installed, for example:
Caylet eSIM
Your iPhone will only use one line at a time as its primary source for mobile data.
If you leave this set to your original SIM card, your phone may continue to use your home carrier's expensive overseas roaming instead of the eSIM you just bought.
Should I Turn On "Allow Cellular Data Switching"?
For most travelers who want to avoid accidental overseas data roaming charges on their original SIM card, we recommend ** turning off**:
Allow Cellular Data Switching
Path:
Settings → Cellular → Cellular Data → Allow Cellular Data Switching
When this is off, your iPhone will not automatically switch its data source back to your original SIM card just because the eSIM loses signal or during a phone call.
However, this setting has a trade-off: if you receive or make a call on your non-data line, you may temporarily lose internet access during the call.
Choose based on your needs:
- ** Priority is avoiding accidental roaming charges:** Leave it OFF.
- ** Need continuous data while talking on your primary number:** Check your home carrier's roaming fees and dual SIM behavior before turning this ON.
Do not turn this feature on just because a generic internet guide suggests it. For most data-only travel eSIMs, leaving it off is the safest way to control data usage.
👉 Related Reading: How Much Data Do I Need? eSIM Data Usage & Plan Comparison Guide
Do I Need to Turn On Data Roaming for the eSIM?
Most travel eSIMs require Data Roaming to be turned on because they provide service by roaming on partner networks at your destination.
Go to:
Settings → Cellular → [Select your Travel eSIM]
And turn on:
Data Roaming
Make absolutely sure you are turning on Data Roaming within the ** Travel eSIM's settings page**, and not accidentally turning it on for your original SIM card.
Recommended setup:
| Line | Cellular Data | Data Roaming |
|---|---|---|
| ** Travel eSIM** | Set as primary data source | Turn ON (as required by product) |
| ** Original SIM Card** | Not used for data | Usually OFF |
A few products may have different requirements, so always follow your order's installation instructions.
👉 Related Reading: For a complete breakdown of Dual SIM management for calls, SMS, and hotspot sharing, see Can a Travel eSIM Use Hotspot, Calls, and SMS? Complete Feature Guide
What Should I Do with My Original SIM Card?
If you want to keep your primary number active to receive calls or texts, you can leave your original SIM card turned on, but you should check the following settings.
Turn Off Data Roaming on the Original SIM
Go to:
Settings → Cellular → [Select your Original SIM]
Turn off:
Data Roaming
Ensure It Is Not the Cellular Data Source
Go to:
Settings → Cellular → Cellular Data
Confirm that your travel eSIM is selected.
Be Aware of Voice and SMS Charges
Even if your mobile data has been switched to the eSIM, your primary number might still incur charges for:
- Answering calls.
- Making calls.
- Sending SMS texts.
- Voicemail.
- Certain Wi-Fi Calling or background roaming activities.
You must confirm the exact fees with your home carrier.
Turn It Off If You Don't Need It
Go to:
Settings → Cellular → [Select your Original SIM]
Turn off:
Turn On This Line
This eliminates the risk of accidentally using your primary number, but it also means you temporarily cannot receive calls or SMS texts on that line.
Do I Need to Configure an APN?
Some travel eSIMs configure the Access Point Name (APN) automatically, requiring no manual input from the user.
If your order explicitly provides an APN, go to:
Settings → Cellular → [Select your Travel eSIM] → Cellular Data Network
Then enter the APN exactly as instructed by the provider.
Note that some iPhones or carrier settings do not allow users to view or edit the APN. If you do not see a "Cellular Data Network" option, it does not necessarily mean the installation failed.
Important rules:
- Do not fill in an APN if you weren't instructed to.
- Do not copy APNs from other eSIM brands.
- Do not randomly edit the "Personal Hotspot" or "MMS" fields.
- Entering the wrong APN can prevent you from accessing the internet.
- A manual APN might be reset after an iOS update.
Always use the APN provided in your Caylet order or specific product instructions.
What Settings Should Be Completed Before Departure?
If your plan allows early installation, we recommend completing these steps before you leave:
- Confirm your iPhone supports eSIM.
- Confirm there is no carrier lock.
- Save your order details and QR code.
- Install the eSIM over a stable Wi-Fi connection.
- Give the travel eSIM a clear label.
- Verify the eSIM appears under your Cellular settings.
- Read the rules on activation and when the validity period starts.
- Note down any required APN.
- Turn off Data Roaming on your original SIM card.
- Do not delete the installed eSIM.
If the plan requires connecting to the destination network to activate, you can simply leave the travel eSIM line turned off until you arrive.
How to Activate the eSIM Upon Arrival?
Once you reach a covered destination, follow these steps in order:
Step 1: Turn On the Travel eSIM
Go to:
Settings → Cellular → [Select your Travel eSIM]
Toggle on:
Turn On This Line
Step 2: Set as Cellular Data Line
Go to:
Settings → Cellular → Cellular Data
Select the travel eSIM.
Step 3: Turn On Data Roaming
Go to:
Settings → Cellular → [Select your Travel eSIM]
Turn on ** Data Roaming** if required by your product.
Step 4: Wait for Network Connection
Your phone may take anywhere from a few seconds to a few minutes to search for and register on the network.
Watch the top corner of your screen for:
- 4G, LTE, or 5G icons.
- A local carrier's name.
- Cellular signal bars.
Step 5: Test the Connection
Temporarily turn off Wi-Fi, then try to:
- Open a webpage in Safari.
- Search for a location in Maps.
- Send a message via an instant messaging app.
- Check your data usage via Caylet's tools.
Do not immediately stream high-definition video or start large downloads, so you don't burn through your data allowance while confirming your settings. If your connection speed is unusually slow, refer to our eSIM Slow Data Troubleshooting Guide.
iOS 26 Travel eSIM Prompts
In supported countries, regions, and plans, iOS 26 may automatically detect a travel eSIM and display a "Turn On Travel eSIM" prompt when you arrive at your destination.
The system might ask you to choose:
- Use Travel eSIM Only.
- Use Travel eSIM alongside your Current SIM.
If you keep both lines active, the iPhone will generally set the travel eSIM as the data source, but your primary number may still incur voice, SMS, or other roaming charges.
This automatic prompt might not appear on all phones, in all regions, or for all products. Even if it doesn't appear, you can always enable the eSIM using the manual steps outlined in this guide.
How to Confirm the eSIM Is Installed Correctly?
Go to:
Settings → Cellular
Check the following:
- The travel eSIM appears in your list of SIMs.
- The line name matches the label you assigned.
- You can toggle the line on or off.
- You can select the eSIM under Cellular Data.
- Upon arrival, it displays a partner network.
- You can access the internet when Wi-Fi is off.
If you have installed the eSIM but are still in your home country, it may not connect to a partner network. This doesn't mean the installation failed—many travel eSIMs only register on a network once you are within the covered destination.
Does Installing the eSIM Immediately Start the Timer?
👉 ** Deep Dive:** When Should You Install and Activate a Travel eSIM?
Not necessarily. It depends entirely on the plan's "Activation Policy."
You need to distinguish between:
- ** Purchase:** Completing the order.
- ** Installation:** Downloading the eSIM profile to your iPhone.
- ** Activation:** The eSIM or plan entering a usable state.
- ** First Connection:** Connecting to a supported network at the destination for the first time.
- ** Validity Period Start:** The moment the plan officially starts counting days.
Different products trigger the validity period at different stages.
Common rules include:
- Starts immediately upon installation.
- Starts upon manual activation.
- Starts upon first connection to a supported network.
- Starts on a specific scheduled date.
- Must be activated within a fixed timeframe after purchase.
Therefore, do not assume the rules of one brand or plan apply to the product you just purchased.
What to Do If It Says "Unable to Activate eSIM"?
Do not delete the eSIM, and do not repeatedly scan the QR code.
Follow this troubleshooting sequence:
- Confirm your iPhone is connected to stable Wi-Fi.
- Toggle Airplane Mode on, wait a moment, and turn it off.
- Go to Settings → Cellular and check if the eSIM has already appeared.
- If it has appeared, turn the line off and then back on.
- Restart your iPhone.
- Go to Settings → General → About and wait to see if a "Carrier Settings Update" prompt appears.
- Ensure your iOS is updated to the latest available version.
- Confirm the QR code hasn't been used on another device.
- Record the exact error message.
- Contact customer support with your order number, phone model, and a screenshot of the error.
Please obscure your phone number, IMEI, EID, serial number, and other private data when sending screenshots.
If the eSIM was successfully added to your Cellular settings, the issue isn't the installation. It's more likely related to your location, data line selection, data roaming settings, APN, or network selection.
Why You Shouldn't Delete an eSIM Arbitrarily
Deleting an eSIM is not the same as temporarily turning it off.
Many travel eSIM QR codes can only be installed a limited number of times—often just once. If you delete it, you might:
- Be unable to scan the original QR code again.
- Have to contact customer support for a replacement.
- Lose any unused data on the plan.
- Invalidate your eligibility for a refund.
- Be completely unable to recover the profile.
If you encounter a problem, prioritize using:
Turn On This Line (Toggle OFF)
Or contact customer support. Do not treat "Delete eSIM" as a standard troubleshooting step like rebooting a computer. For recovery options, check Accidentally Deleted an eSIM? How to Reinstall or Recover It.
Only consider deleting an eSIM if:
- The plan has ended and you are absolutely sure you won't use it again.
- You have successfully transferred it to another device (if the plan allows).
- Customer support explicitly instructs you to delete it.
- You are preparing to sell, trade in, or give away your phone.
Upgrading Your iPhone?
If you plan to get a new phone, iPhones offer a nearby device transfer option, but travel eSIMs have specific restrictions. For details, see Can You Transfer an eSIM to a New Phone?.
What to Do After Your Trip?
When you return home, check your cellular settings.
- Go to Settings → Cellular.
- Turn your primary SIM card back on.
- Set your primary SIM card back as the Cellular Data line.
- Review the data roaming settings for your primary number.
- Turn off the travel eSIM you are no longer using.
- Once you confirm the plan is completely over, you can decide whether to delete it.
In some cases, iOS 26 may automatically turn off the travel eSIM and reactivate your home SIM, but you should always verify manually to ensure you aren't using the wrong line.
Frequently Asked Questions
Can I install the eSIM before I depart?
Many travel eSIMs can be installed in advance, but not all. You must first check whether the plan starts counting down its validity period upon installation, manual activation, or first connection to the destination network.
The QR code is on my iPhone. How do I scan it?
On supported iOS versions and apps, you can press and hold the QR code image in an email or browser, then tap "Add eSIM." If you don't see this option, display the QR code on a different screen or manually enter the installation details.
Do I absolutely need Wi-Fi to install it?
You generally need an active internet connection to download the eSIM profile. We recommend a stable Wi-Fi connection. Some eSIM-only iPhones may support alternative activation methods in certain regions, but you should not rely on these exceptions.
Why does it say "Activating..." after installation?
Your phone might not have reached the coverage area yet, it might still be registering with the network, or the installation might not be fully complete. Check the product's activation rules and do not delete the eSIM immediately.
Do I need to turn on Data Roaming for a travel eSIM?
For most products, yes. Turn it on within the travel eSIM's specific settings, and avoid accidentally turning it on for your original SIM card. Always refer to your specific product's instructions.
Do I need to turn off my original SIM card?
Not necessarily. You can leave your original SIM card active to receive calls or texts. However, you must turn off Data Roaming for that line and ensure Cellular Data is set to use the travel eSIM. Note that voice calls and SMS on your original number may still incur charges.
Is it normal if I don't see a "Cellular Data Network" or APN option after installing?
Yes, this can be normal. iPhones only display the option to edit the APN if the carrier profile permits it. If you haven't received instructions to enter an APN, do not try to modify it manually.
Can I give my QR code to someone else?
No. QR codes and activation details are usually tied to your order and can often only be installed once. Sharing it may result in your eSIM being activated on another device, leaving you without service.
If installation fails, should I delete it and scan it again?
Not recommended. The QR code might not be reusable. First check your network connection, toggle Airplane Mode, review your Cellular list, and note any error messages, then contact customer support.
Official Reference Materials
iPhone interfaces and features may change with iOS updates. Here is Apple's official documentation for reference:
- Apple: Set up an eSIM on your iPhone
- Apple: Use an eSIM while traveling internationally with your iPhone
- Apple: Using Dual SIM with an eSIM
- Apple: About cellular data roaming options for your iPhone and iPad
- Apple: View and edit your Access Point Name (APN) on your iPhone and iPad
- Apple: If you can't set up an eSIM on your iPhone
- Apple: How to erase the eSIM on your iPhone or iPad
Summary
The basic process for installing a travel eSIM on an iPhone is:
- Confirm your phone supports eSIM and is unlocked.
- Connect to a stable Wi-Fi network.
- Go to Settings → Cellular → Add eSIM.
- Scan the QR code or manually enter the details.
- Give the travel eSIM a clear label.
- Upon arrival, set it as your Cellular Data line.
- Turn on Data Roaming as required by the product.
- Turn off Data Roaming for your original SIM card and disable unnecessary cellular data switching.
- Never delete the eSIM arbitrarily when troubleshooting.
Most importantly, installation does not always mean the plan's validity period has started. You must read the specific activation rules for your product before completing the installation.
