An eSIM (embedded SIM) is a digital SIM built into your phone. It does the same job as a physical SIM card – connecting your device to a mobile network – but without a removable plastic card.
How an eSIM works
A traditional SIM is a small chip you insert into your phone. An eSIM is a chip permanently soldered inside your device during manufacturing. Instead of swapping cards, you download a carrier profile onto the eSIM by scanning a QR code or entering an activation code.
Your device can store multiple eSIM profiles at once. This means you can have your regular carrier on one profile and a travel data plan on another, switching between them in your device settings.
eSIM vs physical SIM
| Physical SIM | eSIM | |
|---|---|---|
| Form factor | Removable plastic card | Built into the device |
| Installation | Insert into SIM tray | Scan a QR code or enter an activation code |
| Switching carriers | Swap the card | Download a new profile in settings |
| Multiple plans | One card per slot | Multiple profiles stored on one chip |
| Risk of loss | Card can be lost or damaged | Cannot be lost or ejected |
| Availability | Immediate (in-store purchase) | Instant delivery by email |
Why eSIM is ideal for travel
When you travel internationally, a local data plan avoids roaming charges from your home carrier. With a physical SIM, this means finding a shop at your destination, buying a card, and swapping it into your phone – while keeping your home SIM safe.
With an eSIM, you install your travel data plan before you leave. Your home SIM stays in its slot for calls and texts. When you land, the eSIM connects to a local network automatically. No shop visits, no card swapping, no risk of losing your home SIM.
What you need to use an eSIM
- A device with eSIM support (most smartphones released since 2019)
- An unlocked eSIM slot (not locked by your carrier)
- An internet connection to download the eSIM profile
Check whether your device is compatible in our compatible devices guide.
How Halo eSIM works
When you purchase a Halo data plan, you receive a QR code by email. Scan this QR code to install the eSIM profile on your device. The data plan activates when you arrive at your destination and your device connects to a supported network.
Your Halo eSIM provides mobile data only. It does not replace your phone number or affect your ability to make calls and send texts on your primary line.