What is an eSIM? How it works, how it differs from a SIM card and why travellers use it
What is an eSIM? A plain explanation of the built-in SIM: how it works, how it differs from a SIM card, which phones support it and how travellers use it.
An eSIM is a SIM card built into your phone as a chip. Instead of inserting a plastic card, you download a mobile plan to that chip over the internet, usually by scanning a QR code or tapping a button in an app. It does the same job as a physical SIM: it identifies you to a mobile network so you can use data, and depending on the plan, calls and texts. For travellers the practical effect is simple: you can buy a data plan for your destination online before you leave, install it in a few minutes and keep your normal SIM in the phone for your home number. This guide explains how an eSIM works, how it differs from a SIM card, which phones support it and how to get started.
What is an eSIM, in short?
The "e" stands for embedded. A small chip inside the phone takes the place of the SIM card slot, and mobile plans are stored on it as digital profiles. The key points:
- No card to insert: the plan arrives as a download, so you never need a shop, a SIM tool or a tiny card that can get lost.
- Several plans on one phone: a phone can store more than one eSIM profile and switch between them in the settings. Apple, for example, says an iPhone can hold eight or more eSIMs.
- Works alongside your normal SIM: most eSIM phones are dual-SIM phones, so a travel eSIM for data and your home SIM for calls and texts can be active at the same time.
- Same networks as a SIM card: an eSIM connects to the same mobile networks; speed and coverage depend on the network and the plan, not on the type of SIM.
Your home carrier may also offer your normal contract as an eSIM. This guide focuses on the other common use: prepaid travel eSIMs that you add for a trip.
How does an eSIM work?
Three parts work together when you install an eSIM:
- The chip. Phones with eSIM support have a chip called an eUICC. It can store several SIM profiles, which is what a physical SIM card holds as well, only on a card you can swap.
- The profile. A profile contains the data a network needs to recognise your line. The provider prepares it on a secure server when you buy a plan.
- The download. The QR code or activation code tells your phone where to fetch the profile and which one it is. The phone downloads it over Wi-Fi or mobile data and adds it as a new line.
After the download, the eSIM behaves like a SIM card in a second slot. You can name the line, choose which line handles mobile data, and switch the eSIM on or off. Most phones can store several profiles but only use one or two lines at the same time.
A detail that matters in practice: most QR codes for travel eSIMs can only be used once. If you delete an installed eSIM, you usually need a new code from the provider, so it is better to switch a line off than to delete it. The step-by-step menus are in our guides to installing an eSIM on iPhone and installing an eSIM on Android.
eSIM vs physical SIM card: what is the difference?
| Point | eSIM | Physical SIM card |
|---|---|---|
| Form | Chip built into the phone, plan stored as a profile | Removable plastic card in a slot |
| How you get it | Online, delivered by QR code, link or app | In a shop, by post or at an airport kiosk |
| Setup time | A few minutes, from anywhere with internet | Depends on where you can buy one |
| Several plans | Several profiles on one phone, switch in settings | One card per slot; swapping means opening the tray |
| Moving to another phone | Depends on the provider; travel eSIMs often cannot be moved | Take the card out and put it in the other phone |
| If the phone is lost or stolen | The profile cannot be pulled out and used in another phone | The card can be removed and used elsewhere |
Neither type is faster or more reliable by itself. What changes is how you obtain and manage the plan, which is why eSIMs have become popular for travel: there is nothing to pick up and nothing to swap.
What is a travel eSIM?
A travel eSIM is a prepaid plan for use abroad that you buy online from an eSIM provider. Most of these providers do not run their own networks; they buy access from mobile operators and sell it as data packages for a country, a region or the whole world. A few points that surprise first-time users:
- Usually data only. Most travel plans have no phone number. Calls and messages go through apps such as WhatsApp, and your home SIM stays reachable for calls and SMS codes.
- Technically roaming. The eSIM connects to local networks as a roaming guest, so the phone needs data roaming switched on for that line. You pay the provider's price, not roaming charges.
- Fixed packages or unlimited. You choose an amount of data and a number of days. "Unlimited" plans usually come with a daily allowance at full speed, as explained in our guide to unlimited eSIM plans.
- Country, regional or global. A plan can cover one country or a group of countries; our guide to regional vs global eSIMs explains when each makes sense.
As an example of how many options exist, here is what our database currently holds for Europe:
How a travel eSIM compares with roaming on your home plan and with a local SIM card is covered in eSIM vs roaming vs local SIM.
Does my phone support eSIM?
Most smartphones released in recent years support eSIM, but not all of them, and not every version of a model. As a rough guide:
- iPhone: from the iPhone XS and XR (2018) onwards. iPhones sold in the US since the iPhone 14 have no SIM tray and work with eSIM only. Most iPhones sold in mainland China have no eSIM; only a few of the newest models do.
- Google Pixel: from the Pixel 3 onwards.
- Samsung Galaxy: the S series from the S20 onwards and the foldable Z models, with some regional exceptions.
- Other brands: many recent models from Motorola, Xiaomi, Oppo and others support eSIM, but it varies by model and market.
Two conditions matter besides the model: the phone must not be locked to your home carrier, and the eSIM function must not have been removed for your market. Our eSIM compatibility guide shows how to check your own phone in a minute.
Advantages and limits of an eSIM for travel
What works well
- You can compare plans and buy before the trip, and you are online as soon as you land.
- Your home number stays active for calls and SMS codes from your bank.
- You can keep several travel eSIMs on the phone and switch between them.
- Prepaid plans have a fixed price, so there are no surprise roaming bills.
What to keep in mind
- The phone must support eSIM and be unlocked.
- Installing needs an internet connection, so it is easiest at home before you leave.
- Most travel plans have no local phone number.
- A deleted eSIM often cannot be installed again, and moving it to a new phone is usually not possible.
- Support is online, through chat or email, rather than in a shop.
For long stays, a local SIM card or a local eSIM from a network in the country can be cheaper per GB. For trips of a few days to a few weeks, a travel eSIM is usually the simplest option.
How to get started with a travel eSIM
- Check your phone with our compatibility guide.
- Estimate your data: our guide to how much data you need gives typical amounts per day and per week.
- Compare plans for your destination on our destination pages. Our ranking scores providers on price, coverage, plan terms, transparency and user ratings, as described on the methodology page. Discount codes are on the promo codes page.
- Install the eSIM at home a day or two before you fly; our guide on when to activate an eSIM explains when the plan starts counting.
- After landing, switch the travel line on, choose it for mobile data and allow data roaming for it. If it does not connect, our troubleshooting guide lists the usual fixes.
Questions travellers ask
Is an eSIM better than a physical SIM card?+
Not in terms of signal or speed: both connect to the same networks. The advantage is practical. An eSIM is delivered online, a phone can store several of them, and you can add a travel plan without removing your normal SIM. A physical SIM is easier to move to another phone.
Can I use an eSIM and a physical SIM at the same time?+
Yes, on most eSIM phones. They are dual-SIM phones, so a travel eSIM can handle mobile data while your physical SIM keeps your home number for calls and texts. You choose in the settings which line is used for data.
Does an eSIM need internet to work?+
Only for the installation. Downloading the eSIM profile needs Wi-Fi or another working mobile connection. Once installed, the eSIM connects to mobile networks like a normal SIM card and does not need Wi-Fi.
Can I reuse a travel eSIM on my next trip?+
Sometimes. If the eSIM is still installed and the provider offers top-ups, you can add a new package to the same eSIM, sometimes also for another country. Otherwise you buy a new eSIM. A deleted eSIM usually cannot be reinstalled.
What is an EID?+
The EID is the unique number of the eSIM chip in your phone, 32 digits long. You find it in the phone's settings under About, and on many phones by dialling *#06#. If your phone shows an EID, it has an eSIM chip.
Is an eSIM safe?+
An eSIM is generally considered at least as secure as a SIM card. The profile is downloaded over an encrypted connection and stored on a chip that cannot be taken out of the phone, so a thief cannot simply remove it and use it in another device. As with any SIM, protect your phone with a PIN or passcode.
Written by the eSIM Rankings editorial team. Device support differs by model, market and software version; the manufacturer's and your carrier's information is what counts for your phone. Plan figures in the box come from our database and are refreshed daily. We compare plans on published data and have not tested every plan ourselves.
← All guides