What is an eSIM? A practical guide for travellers

What an eSIM is

A traditional SIM is a small removable card that identifies your phone to a mobile network. An eSIM ("embedded SIM") does the same job, but the chip is built into the phone and can be rewritten. Instead of inserting a card, you download a profile from the provider. The profile holds the details your phone needs to connect to that provider's network.

Because the chip is rewritable, one phone can store several eSIM profiles and switch between them in Settings. You can keep your home line and add a travel line, all on the same device.

Every eSIM-capable device has an EID, a unique number for its embedded chip. Providers use it to deliver a profile to the right device. On an iPhone you can find it under Settings > General > About, a little further down the page.

eSIM vs physical SIM

Both connect you to a mobile network in the same way once they are installed. The difference is in how you get them, change them and look after them.

How to check if your phone supports eSIM

eSIM support depends on the exact model and sometimes on where the phone was sold, so it is worth checking before you buy a plan. Here are the quickest ways, from simplest to most reliable.

On an iPhone

Open Settings and tap Cellular (called Mobile Data in some regions). If your iPhone supports eSIM, you will see an option such as Set Up Cellular or Add eSIM. The EID, if present, is listed under Settings > General > About.

On an Android phone

Menu names vary by brand and software version, but the option always lives in the network or SIM settings:

• Google Pixel: Settings > Network & internet > SIMs > Add SIM > Set up an eSIM.

• Samsung Galaxy: Settings > Connections > SIM manager > Add eSIM.

• Other brands: look in Settings for a section called something like Network, Connections, SIM manager or SIMs, and an option to add or download an eSIM.

You may see advice to dial a code such as *#06# to find out. That is not a reliable test: the official guides from Apple and Google point to the Settings app for the EID, so use Settings instead.

The most reliable check

Look up the manufacturer's specifications for your exact model number, not just the model name. The same phone can be sold in versions with different SIM hardware in different regions, and the model number tells them apart. You can also look your phone up here: Check if your phone supports eSIM.

Three things to confirm as well

• Your phone must not be locked to your home carrier. Apple puts it simply: if your iPhone is unlocked, you can also use eSIM plans offered by other carriers. A travel eSIM comes from a different provider, so a carrier-locked phone may refuse it. Only your carrier can unlock it.

• Install available software updates before you travel, so you are not updating your phone on roaming data.

• Check the region the phone was sold in. In China mainland, for example, Apple lists only certain iPhone models as able to use eSIM there, and says other models cannot install an eSIM profile from carriers in China mainland.

Phones that only work with eSIM

A growing number of phones have no SIM tray at all, which makes knowing how eSIM works more useful every year. According to Apple's own list (updated 5 November 2026):

• iPhone Air and iPhone Duo are eSIM-only wherever they are sold.

• iPhone 18 Pro, iPhone 18 Pro Max, iPhone 17e, iPhone 17, iPhone 17 Pro and iPhone 17 Pro Max are eSIM-only when bought in 12 countries and regions: the United States, the U.S. Virgin Islands, Canada, Mexico, Japan, Guam, the United Arab Emirates, Saudi Arabia, Bahrain, Kuwait, Qatar and Oman. Elsewhere, these models also have a SIM tray.

• Earlier generations (iPhone 14, 15 and 16 models) are eSIM-only when bought in the United States.

If you own one of these phones, an eSIM is the only way to add a travel plan.

Setting up a travel eSIM: best practices

A little preparation makes the difference between being online as soon as you land and troubleshooting at the airport.

1. Choose when to install

Installing needs an internet connection, so the easiest place to do it is at home on Wi-Fi. But when a plan starts counting its days depends on the plan: some start at installation, others only when they first connect to a network at your destination. The plan page tells you which before you buy, and this answer explains both cases: When does my plan's validity start?

2. Turn on the travel line when you arrive

Once you land, make sure the travel eSIM line is switched on and that data roaming is enabled for that line. On an iPhone with two lines, go to Cellular, tap the travel number, then Cellular Data Options, and turn on Data Roaming. On Android, data roaming is in the SIM or mobile network settings; on a dual-SIM phone, check it for the travel line.

3. Keep your home line for calls and texts

Many phones support Dual SIM: Apple, for example, lets you use a physical SIM and an eSIM together, or two eSIMs on iPhone 13 and later. A common setup is to keep your home line active for calls and texts and use the travel eSIM for data.

4. Set the default data line

Choose the travel line as the line for mobile data, so your phone does not use your home line's roaming instead. On an iPhone you can choose which number is used for cellular data. While you are there, give each line a clear label such as "Home" and "Travel" so you always know which one you are changing.

5. Check what your plan includes

Some plans allow sharing your connection through a personal hotspot and some do not, depending on the plan and the network. Check the plan details before you buy rather than assuming. You can browse what is available for your destination here: Browse eSIM plans.

6. Do not delete a profile you still need

If something stops working, check the line's settings (data roaming, mobile data, network selection) before removing anything. Deleting an eSIM removes the plan from your phone, and whether it can be added back depends on the provider. If you are unsure, ask first. For Proalo eSIMs, see: Frequently asked questions