# What is an eSIM? The plain answer for travellers

An eSIM is a SIM built into your phone: you add a plan by link or QR code, with no card to insert, and your home line can stay on beside it.

Published 2026-11-04, updated 2026-11-04. Page: https://inboxesim.com/guides/what-is-an-esim

## What it is

Apple describes an eSIM as an industry-standard digital SIM built into the iPhone, which removes the need for a physical SIM card. Android phones with eSIM work the same way: the plan is downloaded to the phone.

## eSIM or plastic SIM

|  | Travel eSIM | Local plastic SIM |
|---|---|---|
| How you get it | By email or an app, before you leave | At a shop or airport counter |
| Your home SIM | Stays in the phone | Comes out unless the phone takes two SIMs |
| Installing | A link or a QR code, on Wi-Fi | Swap the card, sometimes register it |

## What you need

- A phone that takes an eSIM: iPhone XS, XS Max, XR or later, and many recent Android phones. [Check yours in a minute](/guides/does-my-phone-support-esim).
- A phone that is not locked to your carrier. On iPhone, Settings > General > About must say No SIM Restrictions next to Carrier Lock.
- Wi-Fi or a hotspot while you install it.

## What happens to your number

Nothing has to change. Your home line can stay on for calls and texts while the travel eSIM carries the data. Step by step: [add an eSIM as a second line](https://inboxesim.com/guides/add-esim-second-line).

> Ours is data only, with no app and no account: [pick a destination](/destinations) and the QR arrives by email. Install steps are on the [install page](/install).

## Sources

- Apple: set up an eSIM on iPhone: https://support.apple.com/en-us/118669 (read 2026-11-04)
- Apple: use eSIM while travelling: https://support.apple.com/en-us/118227 (read 2026-11-04)