What is an eSIM, and how is it different from a physical SIM?

What is an eSIM?

The short answer to "what is an eSIM" is a SIM that lives on a chip inside your phone rather than on a card you push into a tray. Apple's own definition is short: an eSIM is "an industry-standard digital SIM built into your iPhone". Android phones that support it work the same way. The "e" stands for embedded.

It does exactly what a physical SIM does. It identifies your phone to a mobile network, so you can make calls, send texts and use mobile data on a plan. The difference is how the plan gets onto the phone. With a plastic SIM, the plan arrives in the post or over a shop counter. With an eSIM, it arrives as a download.

This page is an explainer, written from general knowledge and from Apple's support pages, which we read on 9 November 2026.

What is an eSIM and how does it work?

The chip is fixed. What changes is the profile stored on it, which is the bundle of details a network needs to recognise you. When you buy an eSIM plan, the seller gives you a way to download that profile, usually one of three:

• a QR code you scan with the phone's camera or from the settings screen;
• an app that installs the profile with a tap;
• a carrier activation that pushes it to your phone directly.

Once the profile is installed, it shows up in your settings as a line, next to any physical SIM you have. You choose which line handles data and which handles calls. One chip can hold several profiles. Apple says an iPhone can manage "up to eight or more eSIMs", though not all of them run at the same time.

To use an eSIM from a company other than your own carrier, the phone has to accept it. Airalo's install guide, for example, lists a phone that supports eSIM and is network-unlocked as the starting point. A phone that is locked to its carrier will refuse other carriers' profiles, eSIM or not.

eSIM vs physical SIM: what actually differs

Neither one is faster or better on the network. Speed and coverage depend on the network and plan behind the SIM, not on whether the SIM is a card or a download.

Is an eSIM better than a physical SIM?

For most people with a recent phone, it is more convenient, and for travel it is usually the better tool. It is not better in every case.

Where an eSIM wins: you can buy and install a plan before you leave home, so you land connected. You can keep your home SIM in the phone at the same time, which matters if banks or apps text you codes. And there is no tiny card to lose in a hotel room.

Where a physical SIM still wins: moving it between phones is trivial, while moving an eSIM depends on your carrier's process. Older and cheaper phones may not support eSIM at all. And in some countries a local physical SIM from a supermarket or shop is cheaper than any eSIM you can buy online. Our country guides say where that is true, and so does the last column of the cheapest eSIM table.

Some phones have made the choice for you. Apple's eSIM page refers to iPhone models that are eSIM-only, which have no SIM tray.

What is an eSIM for travel?

A travel eSIM is a prepaid data plan for another country that you install as a second line. You keep your home number on your normal SIM or eSIM, switch mobile data to the travel line, and pay the travel eSIM's price instead of your carrier's roaming charges.

Most travel eSIMs are data plans. Calls and texts carry on through your home line, or through apps over data. A few sellers add a number; see whether Airalo gives you a phone number for one example.

The brands this site compares are Airalo, Holafly, Nomad, Saily and eSIMCard. They differ mainly on price per gigabyte and on whether they sell unlimited plans. The cheapest eSIM page ranks them by what a gigabyte actually costs, and the best eSIM for international travel covers multi-country trips.

How does an eSIM work internationally?

Abroad, a travel eSIM connects to a local network in the country you are visiting, through an agreement between the seller and that network. Your phone often treats this as roaming, which is why install instructions sometimes tell you to switch data roaming on for the eSIM line. Airalo's iPhone guide says to turn Data Roaming on or off "as instructed in your Airalo app".

The usual set-up on a dual SIM phone is: home line on, but with its own data roaming off; travel eSIM line on, set as the mobile data line. That keeps your number reachable for texts while stopping your home carrier from charging for data. On an iPhone, Apple puts the switch under Settings, Cellular, then Cellular Data Options, for each line.

Apple also notes that you can buy an eSIM when you travel and set it up in Settings, although installing before you leave, while you still have Wi-Fi, is the safer order.

How do eSIMs work on iPhone?

On an iPhone, eSIM plans live under Settings, then Cellular (Mobile Data in some regions). Each installed plan appears as its own line with a label you can rename, such as "Travel" or "Home". From there you pick which line is used for cellular data and which is the default for calls. If you want a walk-through for one seller, see how to install an Airalo eSIM on iPhone.

What does deleting an eSIM do?

Deleting an eSIM removes the profile from your phone. It does not cancel the plan. Apple's guidance is to contact your carrier if you want to cancel your cellular plan, and it warns that if you erase an eSIM "you'll need to contact your carrier to get a new one".

Apple also advises not to erase an eSIM as a troubleshooting step unless your carrier tells you to. For a prepaid travel eSIM, read the seller's help pages before you delete anything, because there may be no way to put the same profile back with its remaining data. The safe rule is to delete a travel eSIM only once its data is used up or its validity has ended.

How to tell whether your phone takes one

Check before you buy anything. Our eSIM compatible phones list covers the main models, and a phone also has to be unlocked to take another company's eSIM. If your phone fails either test, a physical local SIM is still the answer.