What is an eSIM?
An eSIM is a SIM card built into the phone as a chip. Instead of a plastic card you download a profile: scan a QR code, and the phone joins a network. A travel eSIM, also sold as an international SIM or travel SIM, is a data-only profile from a network in the country you are visiting. You install it at home over Wi-Fi and switch it on when you land; your own SIM, number and WhatsApp stay exactly as they are.
How an eSIM works, step by step
eSIM vs a physical SIM card
| Travel eSIM | Local SIM card | |
|---|---|---|
| How you get it | By email, before the trip | At the airport or a carrier shop, often against a passport |
| Install | Two minutes at home over Wi-Fi | Swap the card, sometimes register it |
| Your number | Stays in the phone on your own SIM | Card is out; calls to your number miss you |
| Phone number on the plan | None: data only | Local number, calls and SMS |
| Several at once | Phones store several profiles; two lines active | One slot, one card |
| Moving to another phone | Installs once; a new phone needs a new eSIM | Move the card |
| Works on | iPhone XS and newer, most recent Android flagships | Any unlocked phone |
Which phones support eSIM
iPhone XS (2018) and newer, Samsung Galaxy S20 and newer with the Z Fold and Z Flip lines, Google Pixel 4 and newer. Units sold in mainland China are the main exception. Budget Android lines, such as Galaxy A, Redmi and POCO, mostly ship without eSIM. Makers also sell the same model with and without eSIM depending on the country, so the one-minute check in Settings beats any list: an EID row under General → About on iPhone, an "Add eSIM" entry in the SIM settings on Android.
What a travel eSIM costs
Plans are priced by data volume and validity, from about four dollars for a gigabyte to a few tens of dollars for an unlimited month. Every country page shows what each plan costs per day and per gigabyte, and for visitors from Australia, the US and Canada, what the home carrier's roaming pass would cost for the same days.
What stays the same, and what changes
Stays: your number, WhatsApp, iMessage, banking apps and two-factor codes by SMS, because your own SIM stays in the phone. Changes: data comes from the local network through the eSIM, so streaming, maps and calls over WhatsApp cost what the plan cost, nothing more. Calls and texts over your own SIM still roam at your carrier's rates, which is why data roaming for that SIM goes off.
Guides
Rules of the country still apply
A handset that supports eSIM still meets whatever the destination requires: an identity check before a local SIM is sold, a handset registry, an APN typed by hand. Those rules sit with the country, not the phone. The rules section reads them from the primary documents, one country at a time.