What isan eSIM?
An eSIM is a digital SIM built into your phone — no plastic card to post, insert or swap. You download a network profile by scanning a QR code and you're connected in minutes. (Fuse is a multi-network eSIM that connects to all four UK networks — more on that below.)
What is an eSIM?
An eSIM is a digital SIM built into your phone — there's no plastic card. You activate it by scanning a QR code, so you're connected in minutes with nothing to post, insert or swap. Most phones from 2018 onwards (iPhone XS+, Samsung Galaxy S20+, Google Pixel 3+) have an eSIM built in.
A SIM, without the plastic
An eSIM (embedded SIM) does exactly what a normal SIM card does — it tells a mobile network who you are so your phone can get signal and data. The difference is that the chip is already built into your phone. Instead of waiting for a card in the post and sliding it into a tray, you download a network profile over the internet, usually by scanning a QR code.
Because the profile is digital, an eSIM activates in minutes, can hold several network profiles at once, and leaves your physical SIM slot free for a second line. Almost every phone released since 2018 has an eSIM built in.
eSIM vs physical SIM
| Feature | Fuse | Physical SIM |
|---|---|---|
| Format | Digital — built into your phone | Plastic card |
| Get connected | Scan a QR code, minutes | Wait for the post / shop visit |
| Hold multiple network profiles | ||
| Frees the SIM tray for a second line | ||
| Can be physically lost or stolen | ||
| Move to a new phone | Re-download the profile | Move the card |
Format
Get connected
Hold multiple network profiles
Frees the SIM tray for a second line
Can be physically lost or stolen
Move to a new phone
Does your phone support eSIM?
Most smartphones from 2018 onwards do — iPhone XS and newer, Samsung Galaxy S20 and newer, Google Pixel 3 and newer, and most other recent flagships. The quickest check is to dial *#06# and look for an EID number — only eSIM-capable phones have one.
From sign-up to signal in minutes.
An eSIM is digital, so there's no SIM in the post and no shop visit. Here's the whole process.
Check your phone supports eSIM
Dial *#06# or look up your model on our devices list. iPhone XS+, Galaxy S20+, Pixel 3+ and most 2020+ flagships work.
Choose a plan
Pick the data you need. From £5.99/mo, no contract.
Scan your QR code
We email it instantly. Open your camera, scan, follow the prompts.
Connected in minutes
No waiting for the post. Live within the hour.
Move it to a new phone
Re-issue your eSIM from your account when you upgrade.
Encrypted & secure
Tied to your device — nothing to physically steal.
Why Fuse
Not just an eSIM — a multi-network eSIM
A normal eSIM still ties you to one network. Fuse is a multi-network eSIM — one digital SIM that connects to all four UK networks (EE, Three, Vodafone and O2) and automatically switches to whichever has the strongest signal where you are. Not sure yet? Test it on your own phone with a free 7-day trial.
EE
UK's largest 4G network and a leader in 5G rollout. Covers 99% of the UK population with 4G.
Three
Generous data and strong 5G in urban centres, with reliable high-speed mid-band coverage.
Vodafone
Dependable nationwide coverage with particularly strong signal in rural areas.
O₂
One of the UK's most trusted networks with excellent indoor coverage and a growing 5G footprint.
Travel-ready
Your eSIM works in 120+ countries.
One of the big advantages of an eSIM is travel. Land at your destination and your Fuse eSIM connects to a local partner network automatically — no local SIM, no surprise roaming bills. Included on Pulse and Surge plans.
See roaming countriesMore on eSIM
Can You Have Two eSIMs on One Phone?
Most phones can store multiple eSIM profiles — but how many can you actually use at once? Here's everything you need to know about dual eSIM on iPhone and Android.
Blog · 6 min read
Data SIM for a Smartwatch or Wearable
Cellular smartwatches need their own data connection to work independently. Here's how eSIM works in wearables and what to look for in a UK data SIM.
Blog · 6 min read
Does an eSIM Work Without Signal?
An eSIM needs signal like any SIM — but a multi-network eSIM fixes dead zones by switching between all four UK networks automatically.
Blog · 6 min read
Does an eSIM Work Without Wi-Fi?
Once active, an eSIM works entirely on the cellular network — no Wi-Fi needed. Here's when you do need it, and when you don't.
Blog · 6 min read
Ready when you are
Try an eSIM
free for 7 days.
No plastic SIM, no contract. Scan one QR code and get all four UK networks for the price of one.
No contract. Cancel anytime.