What Is an eSIM and How Does It Work?

How Is This Different From a Normal SIM?

A traditional SIM card is a physical chip tied to one carrier. When you travel, you either pay roaming charges on your home SIM, or you buy a local SIM at the airport (usually overpriced) and swap it in. Both options are inconvenient.

An eSIM lets you add a second network plan to your phone without touching the physical SIM slot. Your UK number stays active. Your travel data plan activates automatically when you land. You switch between them in your phone's settings.

How Do You Set Up an eSIM?

1. 1Buy a plan from a provider like Airalo, Yesim, Saily or Drimsim
2. 2You receive a QR code via email or in the app
3. 3Go to Settings → Mobile Data → Add eSIM on your phone
4. 4Scan the QR code — done
5. 5Activate when you land, or set it to activate automatically

The whole process takes about 3 minutes. You can do it from home the night before you fly.

Does Your Phone Support eSIM?

• iPhone: XS or later (2018+). iPhone 14 onwards is eSIM-only in the US.
• Samsung: Galaxy S20 and later, most Galaxy Z Fold/Flip models
• Google Pixel: Pixel 3 and later
• Other Android: Check your phone's spec sheet for "eSIM" support

Note: some phones bought on contract may be carrier-locked and can't use third-party eSIMs until unlocked. Contact your UK carrier if unsure.

Is an eSIM Cheaper Than Roaming?

Almost always yes. UK carriers typically charge £2–5 per day for a roaming add-on. A 5GB European eSIM plan from Airalo or Yesim costs around £6–10 for the entire trip, with no daily charges regardless of whether you use it.