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.