What is an eSIM?
An eSIM is a digital SIM card built into your phone. Instead of inserting a plastic SIM, you scan a QR code or tap a link and a mobile plan is downloaded onto a secure chip inside the device. It takes about a minute and works alongside your normal SIM, so you can keep your home number while using a travel data plan abroad.
An eSIM is a digital SIM card built into your phone. Instead of inserting a plastic SIM, you scan a QR code or tap a link and a mobile plan is downloaded onto a secure chip inside the device. It takes about a minute and works alongside your normal SIM, so you can keep your home number while using a travel data plan abroad.
How an eSIM works
An eSIM (embedded SIM) is a small reprogrammable chip soldered into your phone, tablet or smartwatch. It replaces the physical SIM tray with a software profile that any supported carrier — like A.R.I.A Mobile — can write to remotely.
When you buy a travel eSIM, the carrier issues a unique activation code. You scan it once, the phone downloads the profile over Wi-Fi, and you have a working mobile plan in under a minute. No shop visits, no plastic, no waiting for a courier.
Why travellers use eSIMs
- No SIM swap. Your home SIM stays in place. Calls and texts on your normal number still arrive while you use the travel eSIM for data.
- Activate before you fly. Buy and install in the UK, then switch it on the moment you land.
- Multiple plans. Modern iPhones and Pixels store 8+ eSIM profiles. Keep one for each country you visit regularly.
- No roaming bills. You pay a fixed amount for a known data allowance. No surprise £80 charges at the end of the trip.
What you need
- A phone made roughly after 2018 (all iPhones from XS onward, Pixel 3+, Samsung S20+, and most flagship Android phones).
- The device must be unlocked to other networks.
- A Wi-Fi connection at the moment you install — you only need data once your eSIM is active.
People also ask
- How does an eSIM work?
When you buy an eSIM you receive a QR code or activation link. Your phone reads it, downloads a mobile profile onto its built-in eSIM chip, and connects to the local network the carrier has roaming agreements with. From that point it behaves exactly like a physical SIM — except you can install several profiles and switch between them in Settings.
- Can I have two eSIMs active at the same time?
Yes. Modern iPhones (XS and later) and most flagship Androids let you store many eSIM profiles and have two active at once — typically your home line plus a travel eSIM. Calls and texts route through whichever line you choose as default, while data can be set to use the cheaper travel eSIM automatically.
- Is my phone eSIM compatible?
Almost every flagship phone released since late 2018 supports eSIM. That includes all iPhones from XS onward, Google Pixel 3 and later, and Samsung Galaxy S20-and-newer plus the Z Fold and Z Flip ranges. The other requirement is that the phone is unlocked to other networks — most UK contract phones are unlocked by default since 2021.
- eSIM vs roaming — which is cheaper?
For almost every trip outside the EU, a travel eSIM is dramatically cheaper. A typical UK carrier charges £6 per day for roaming data outside Europe — that's £84 for a two-week trip with a 500 MB daily cap. The same trip on an A.R.I.A Mobile eSIM is around £10-£20 for 10-20 GB of data, with no daily caps and no bill shock.
A.R.I.A Mobile is a global eSIM connectivity platform built for travellers, athletes, teams and businesses. It provides instant digital connectivity in more than 180 countries and powers modern communication tools such as WhatsApp, Teams, Zoom, FaceTime, Telegram, Maps and Email. Learn more.