What is an eSIM?
An eSIM is a digital SIM that lets you activate a mobile plan without inserting a physical SIM card into your phone. Your phone has an embedded SIM component, so you can download a mobile plan through its settings instead of inserting a plastic card.
It works much like a regular SIM. Depending on the plan, an eSIM can provide mobile data, calls and text messages. Many travel eSIMs are data-only, meaning they provide internet access but don't include a traditional phone number, calls or SMS.
For travellers, the main advantage is convenience. You can buy an eSIM online, install it before leaving home and use it to connect to a supported mobile network when you arrive at your destination.
How does an eSIM actually work?
Your phone contains a built-in SIM component that can securely store digital mobile network profiles. When you buy an eSIM plan, the provider supplies the information needed to download one of those profiles.
This is commonly done using a QR code, although some providers support installation through an app or manual activation details.
Once installed, the eSIM identifies your device to the mobile network, allowing it to connect according to the plan you've purchased.
The important distinction is that installing an eSIM and starting its plan validity are not always the same thing. Installation downloads the profile to your phone; the validity countdown may start on installation, first connection or another event specified by the provider.
How to install and activate a travel eSIM
Most travel eSIMs follow a similar process, although the exact steps depend on your phone and provider.
- Choose a plan: Select the destination, data allowance and validity period you need.
- Receive your eSIM: The provider supplies a QR code, app-based installation or manual activation details.
- Install the eSIM: Open your phone's SIM settings and follow the installation instructions. You'll normally need an internet connection.
- Select it for mobile data: Choose the travel eSIM as your preferred mobile data line when you're ready to use it.
- Connect abroad: Once you're in a supported destination, enable the required settings and allow the eSIM to connect to a local network.
On an iPhone, installation normally starts under Settings → Mobile Service → Add eSIM (or Cellular, depending on your region).
On Samsung Galaxy devices, look under Settings → Connections → SIM manager → Add eSIM. Other Android devices use slightly different menus.
Many travel eSIMs need data roaming enabled on the travel eSIM line because they connect through partner networks. Check the provider's instructions. Keep data roaming disabled on your home line if you want to avoid accidental home-network data charges.
Can I keep my phone number when using a travel eSIM?
No. Installing a travel eSIM does not automatically replace your existing SIM card, cancel your mobile contract or change your phone number.
On a compatible dual SIM phone, you can keep your regular line available while using a separate travel eSIM for mobile data.
For example, imagine you're travelling from the UK to Japan. You could keep your UK SIM active for receiving calls and verification texts while using a Japanese travel eSIM for maps, browsing and WhatsApp.
Your normal mobile provider may still charge for calls, texts or other roaming services used through your home line. Set the travel eSIM as the mobile data line and check that automatic mobile-data switching to your home line is off if your phone offers that setting. Disabling data roaming on your home line helps prevent unexpected data charges.
Some phones support multiple installed eSIM profiles but only a limited number of active lines at once. The exact combinations depend on your device.
Can you still use WhatsApp with an eSIM?
Yes. You can continue using WhatsApp with your existing phone number while connected through a data-only travel eSIM.
WhatsApp messages, voice calls and video calls use an internet connection, so you don't need a new phone number just because you've changed which SIM provides your mobile data. Internet calling can still be subject to local network restrictions in some destinations.
Avoid changing your WhatsApp number or reinstalling the app unnecessarily. If your account needs to be verified again, you may need access to your original number to receive a code.
eSIM vs physical SIM: what's the difference?
Both technologies allow compatible devices to connect to mobile networks. The main difference is how the SIM is installed and managed.
| Feature | eSIM | Physical SIM |
|---|---|---|
| Installation | Downloaded digitally | Card inserted into device |
| Physical card required | No | Yes |
| Buying before travel | Often available online with digital delivery | Depends on seller and delivery method |
| Switching plans | Managed through device settings | May require swapping cards |
| Phone compatibility | Requires eSIM support | Requires a compatible SIM slot |
| Calls and SMS | Depends on the plan | Depends on the plan |
| Mobile network coverage | Depends on provider and partner networks | Depends on provider and partner networks |
An eSIM isn't automatically faster than a physical SIM. Connection speed depends on the network, coverage, device capabilities, congestion and any restrictions attached to the plan.
The main advantage is being able to purchase and manage mobile plans without physically changing SIM cards.
Do all phones support eSIM?
No. Your phone must support eSIM technology, and it normally needs to be network-unlocked to use a travel eSIM from a different provider.
Many recent iPhone, Samsung Galaxy and Google Pixel models support eSIM, but availability can differ between regional versions of the same phone.
For example, some phones sold in mainland China have different SIM configurations from models sold in Europe or North America. That's why checking the exact device matters more than relying on its model name alone.
How to check whether your phone supports eSIM
On an iPhone, open Settings → Mobile Service or Cellular and look for an option to add an eSIM.
On Samsung Galaxy, open Settings → Connections → SIM manager and check whether an Add eSIM option is available.
You can also dial *#06# on many phones and look for an EID number. An EID is an identifier associated with the device's eSIM functionality.
The absence of a particular menu option or EID display isn't always conclusive. If you're unsure, check the manufacturer's specifications for your exact regional model.
Remember that eSIM compatibility and network unlocking are separate requirements. A phone can support eSIM but still be locked to a particular mobile operator. See our guide to checking whether your phone is unlocked before purchasing.
Are travel eSIMs cheaper than roaming?
They can be, particularly when your home mobile provider charges expensive roaming rates outside your included destinations.
For example, a traveller visiting the United States might find that purchasing a dedicated travel eSIM costs less than paying their UK operator's daily roaming charge for a week.
However, that isn't always the case. Some mobile contracts already include roaming in certain countries, while others offer reasonably priced travel passes.
Before buying, compare the total cost, data allowance, validity period and coverage. A cheaper package isn't necessarily better value if it provides too little data or has restrictive speed limits. For a full breakdown, read our eSIM vs roaming vs local SIM comparison.
Can you use one eSIM in multiple countries?
Yes, provided the plan includes all the countries you're visiting.
Travel eSIMs are available as single-country plans, regional packages and broader international plans.
For example, a regional Europe eSIM might cover several countries on the same trip, avoiding the need to purchase a separate plan each time you cross a border.
Always check the actual list of supported countries. A plan advertised for a region doesn't necessarily include every country within it, and coverage or network access can vary between destinations.
What happens when your eSIM runs out of data?
When a fixed-data eSIM reaches its allowance, mobile internet access through that plan normally stops or becomes restricted, depending on the provider's terms.
Some providers allow you to add more data to the same eSIM. Others require you to purchase and install a new package.
Your eSIM profile doesn't necessarily disappear when the allowance expires. However, an expired or exhausted package won't continue providing normal service unless the provider supports renewal or top-ups.
If you expect to use maps, social media, video calls and other apps throughout your trip, choosing an appropriate allowance beforehand can reduce the chance of running out unexpectedly. Our travel data allowance guide compares 1GB, 3GB, 5GB, 10GB and larger packages.
Are eSIMs safe to use?
eSIM technology uses established mobile network security mechanisms and removes the need to handle a removable SIM card. However, using an eSIM doesn't automatically make your internet activity private or protect you from scams.
Buy from a reputable provider, keep your activation QR code private and avoid sharing installation details publicly.
Be particularly careful with QR codes received from unknown sources. An eSIM activation code can contain information needed to download a mobile profile and should be treated as sensitive.
Frequently asked questions
Do I need Wi-Fi to install an eSIM?
You normally need an internet connection to download an eSIM profile. Wi-Fi is often the easiest option, particularly before travelling. Some devices and providers support alternative installation methods.
Can I install an eSIM before travelling?
Yes, many travel eSIMs can be installed before departure. Check the activation policy first because some plans begin their validity period when installed rather than when first used abroad.
Can I delete an eSIM and install it again?
Not always. Some travel eSIM activation codes can only be used once. Deleting the profile may prevent you from reinstalling it without assistance or purchasing a replacement. Don't delete an eSIM unless your provider instructs you to do so.
Does an eSIM give you a new phone number?
Only if the plan includes one. Most data-only travel eSIMs don't provide a traditional phone number, while some plans include voice and SMS services.
Does an eSIM work without a physical SIM?
Yes. A compatible device can use an eSIM without a physical SIM installed. You only need a physical SIM if you want to use a separate service that requires one.
Is an eSIM better than a physical SIM for travelling?
An eSIM is often more convenient because you can purchase and install it digitally. However, a local physical SIM may offer better value or specific features in some destinations. Compare the available options rather than assuming one format is always better.
Find the right travel eSIM for your trip
An eSIM makes it possible to arrange mobile connectivity before leaving home, without visiting a phone shop or swapping physical SIM cards.
The important things to check are whether your phone is compatible, which networks and countries the plan covers, how much data you receive and when the validity period begins.
On eSIM Indexer, you can compare travel eSIM plans from different providers by destination, data allowance, validity and price, helping you choose an option that suits your trip.
Editorial note: Device menus, activation rules, network access and package terms differ by phone and provider. Check the specific plan details before purchasing.
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