How to use iMessage with a travel eSIM?

You can still use iMessage with your primary line!

Jan 10, 2024 · 2 min read

summary

What is iMessage? Are they the same as SMS/MMS?
Checking your iMessage settings
Tips for eSIM management and iMessage configuration

Using a travel eSIM when traveling does not mean that your contact number has to change. You can retain your primary phone number on your messaging and social apps, while using your travel eSIM for data and connectivity. But if you have installed an eSIM, and noticed that the phone number of your iMessage had changed, fret not — it is likely to just be an issue with the settings that can be quickly fixed!

What is iMessage? Are they the same as SMS/MMS?

For iPhone users, iMessage is almost synonymous to SMS/MMS - but are they really the same?

Fundamentally, iMessages are texts, photos or videos you can send to another Apple device (iPhone / iPad / Mac), and the messages are sent over the internet, using either WiFi or Mobile Data. Messages sent via iMessage will consume your mobile data (if WiFi is not available). These messages are not encrypted and appear in blue text bubbles in your Message app.

On the other hand, SMS/MMS are messages that you can send to other devices (including non-Apple devices). SMS/MMS will be sent via cell, and will draw from the the SMS/MMS quota of your phone plan. These messages are not encrypted and appear in green text bubbles in your Message app.

Checking your iMessage settings

Installing a travel eSIM in a secondary eSIM slot on your device does not change nor deactivate your primary line and phone number.

However, some people might have faced the problem where after the installation of an eSIM, you can no longer send or receive messages on your iMessage or that your phone number had changed. This is often a result of an incorrect setting.

Run through a couple of checks on your iPhone to confirm that the settings are correct:

On your iPhone, go to Settings > Messages.
Check that iMessage is turned on.
Check that the correct line has been selected for 'Send & Receive' under iMessage & FaceTime.
Ensure that the line selected is your primary line (i.e. the one that you usually use). Sometimes, upon installation of a new eSIM, your device might automatically update this setting to the newly installed eSIM.
If the eSIM that has been configured for iMessage and FaceTime is incorrect, select the option 'Send & Receive', and choose the correct line.
You should now be able to use your iMessage and FaceTime as per normal.
In case you are still unable to do so, restart your device.

Tips for eSIM management and iMessage configuration

To avoid confusion when configuring your iMessage when using a travel eSIM, here are some tips and best practices:

Name your SIM cards and eSIMs: while naming your eSIMs may seem trivial, it is a simple trick for eSIM management, and will help to avoid confusion of which eSIM has been configured for your messaging apps.
Add your Apple ID and email address to your iMessage: If you have set your Apple ID and email address, you will have the option of sending and receiving messages using your email address. This way, you will not need to worry about your messages being lost even if you really did change numbers.
Disable 'Send as SMS' option while overseas: Again, this might seem like a trivial step. However, disabling this option will help you to avoid accidentally incurring overseas SMS charges in case your iMessage wasn't configured correctly or if you are sending a message to another device that doesn't have iMessage available.

💡Do not disable your primary line entirely! Disabling your primary line will also mean you will not be able to receive calls or SMSes on that line - which might not be ideal in case you need to receive OTPs for banking transactions.