What Is an eSIM and How Does It Work? A Plain-English Guide for Travellers

The one-sentence answer

An eSIM is a SIM card that is built into your phone as a chip. Instead of inserting a plastic card, you download the operator's profile by scanning a QR code.

Everything else follows from that. You can add a mobile plan in a minute, keep several plans on one phone, and buy a travel plan before you leave home.

How it works

Inside every eSIM-capable phone there is a small chip called an eUICC, the "embedded SIM". It has a unique ID called the EID.

When you buy an eSIM, you receive a QR code (or an activation code). Scanning it tells your phone to download an operator profile from a secure server and store it on the chip. The profile contains everything a plastic SIM would: the identity the network uses to recognise the line (the IMSI) and the encryption keys.

A few useful facts:

• Your phone can store several profiles, for example your home line and one or more travel eSIMs. Usually one or two are active at a time.
• Each profile has an ICCID, a long number that identifies that particular eSIM. It is the reference number support asks for.
• A QR code is usually single-use. Once a profile is installed, the same code generally cannot be installed again, so do not delete an eSIM you still need.

Travel eSIM vs your normal SIM

The normal setup is both at once: your main SIM stays on for calls, SMS and bank codes, while the travel eSIM handles mobile data. WhatsApp, Telegram and other apps keep working with your usual number because they only need internet.

Does my phone support eSIM?

The quickest test: open the phone app and dial *#06#. If you see a line called EID, your phone has an eSIM chip.

As a rough guide:

• iPhone: iPhone XS, XR and every newer model support eSIM. Recent US models are eSIM-only. iPhones sold in mainland China generally do not support eSIM (they use two physical SIMs instead).
• Google Pixel: most models from the Pixel 3 onwards.
• Samsung Galaxy: flagship S, Z Fold and Z Flip models from around 2020 onwards. Many A-series and budget models do not.
• Other Android phones: it varies by model and even by the country it was sold in. Always test with *#06#.

Two more things must be true:

1. The phone is not carrier-locked. A phone locked to one operator will refuse other operators' eSIMs. Ask your carrier to unlock it before you travel.
2. The phone is connected to the internet while installing, on Wi-Fi or mobile data, so it can download the profile.

Our phone check walks you through all of this.

Installing a travel eSIM

• iPhone (one tap): on our order page, press "Install on iPhone" and follow the prompts.
• iPhone (QR): Settings → Mobile/Cellular → Add eSIM → Use QR code.
• Samsung: Settings → Connections → SIM manager → Add eSIM → scan QR.
• Google Pixel: Settings → Network & internet → SIMs → Download a SIM → scan QR.
• No second screen to scan from? Choose "Enter details manually" and paste the SM-DP+ address and activation code from your order page.

After installing, give the line a name like "NoIDeSim". Do not worry if it says "No service" at home. It will connect in your destination.

Common mistakes

• Deleting the eSIM after the trip "to tidy up" while there is still data on it. The QR usually cannot be reused.
• Forgetting data roaming. Travel eSIMs connect as roaming, so data roaming must be on *for the eSIM line*. Keep it off on your main SIM.
• Wrong line selected for data. In settings, choose the travel eSIM for mobile data.
• Buying for a locked phone. Unlock first, then buy.

If something does not work on arrival, see eSIM not working abroad: the fixes, in order.

Where to go from here

• Choose a plan: single country, region or global, starting from $1.20.
• Pay without a card: crypto or Telegram Stars.
• Care about privacy? Read no-KYC eSIM explained.

FAQ