Check your device
Most phones from 2018+ support eSIM — iPhone XR and up, Pixel 3 and up, Galaxy S20 and up. Our checker confirms in 2 seconds.
How it works
Every UK network.
Auto-switching.
One eSIM that talks to EE, Three, Vodafone and O2. Your phone picks the strongest signal automatically — no configuration, no swapping, no thought.
Set up in 60 seconds
Five steps. No call centres. No SIM in the post.
Choose your plan
Spark, Pulse or Surge. All include all four UK networks. Cancel any time — 30-day rolling, no contract.
Get your eSIM
Install it straight from the Fuse app — one tap, no scanning needed. Or use the QR code from your email if you signed up on a different device.
Activate your eSIM
Tap "Continue" to install. Set Fuse as your data line. Phone connects to the strongest of the four networks automatically.
You're connected
That's it. Your phone now picks the best of EE, Three, Vodafone and O2 — wherever you are. Nothing else to configure.
A real journey
Manchester to London.
Four networks. Zero buffering.
Here's what actually happens on a single train journey when you're carrying a Fuse multi-network eSIM. Five invisible network changes in two hours. Your phone makes every decision automatically — you do nothing.
Manchester Piccadilly
Boarded the 08:32 to London Euston. Phone connected to the strongest local signal — O2.
O2
08:32
Stockport
O2 weakened in a cutting. EE was strongest in range. Phone moved over without dropping the Spotify stream.
Switched to EE
08:51
Crewe junction
Long rural stretch. Vodafone's mast on the approach edged out EE. Switch took under a second.
Switched to Vodafone
09:24
Rugby
Train passed within a hundred metres of a Three tower. Phone took the stronger signal.
Switched to Three
09:58
Milton Keynes
Mainline coverage tightened. EE became the strongest on the final leg into London.
Switched to EE
10:30
London Euston
Arrived. Five invisible network changes. One unbroken connection.
EE
10:54
What you noticed during the journey: nothing. The album kept playing. The Zoom call didn't drop. The download finished.
Illustrative example. Your phone makes the same decisions in real time, based on the actual signal strength of all four UK networks wherever you happen to be.
Always measuring
Your phone silently checks signal strength across all four UK networks in the background, every few seconds.
Switches only when worth it
Built-in hysteresis. The phone only changes networks when another is meaningfully stronger — no flapping back and forth.
Under a second
The handover completes in under a second. Faster than the time it takes you to look up from your phone.
Nothing pauses
Your stream keeps streaming, your call keeps calling, your download keeps downloading. The switch is invisible to apps.
Under the hood
Multi-IMSI eSIM.
Carrier-grade switching.
Without the jargon: your phone holds four network identities at once, and the strongest one wins.
One eSIM carries four network profiles
Your phone sees a single eSIM — but it can authenticate against any of EE, Three, Vodafone or O2 in real time. The handover is invisible. Calls don't drop, downloads don't pause, streams don't buffer.
Strongest signal wins
Background scanning every few seconds. Switches when a stronger network is available.
Sub-second handoff
Network change completes faster than you'll notice.
Works with dual-SIM
Keep your existing SIM for calls. Fuse handles data.
No app required
The intelligence lives in the eSIM profile, not an app.
One install, lifetime use
Scan once. Never reinstall. Move phones via your account.
An eSIM (embedded SIM) is a digital SIM built into your phone. Instead of a physical SIM card, your phone's connectivity is activated digitally. This means no waiting for a SIM card in the post — you can be connected in minutes.
Yes. Most eSIM-compatible phones support dual SIM — one physical and one eSIM. You can use your Fuse eSIM for data alongside your existing physical SIM for calls and texts.
No. Fuse is data-only — your existing SIM keeps your number for calls and texts. You don't transfer your number; you just add Fuse as a second data line.
Most customers are connected within 60 seconds. You scan a QR code and follow the on-screen instructions. No technical knowledge required.
If your phone doesn't support eSIM, you can't use Fuse at this time. Use our device checker to confirm — most phones from 2018 onwards do.
Yes. From your account dashboard, generate a new QR code and scan it on your new phone. Your old phone is automatically deactivated.
Sixty-second install
Try Fuse free.
Switch back any time.
Seven days of multi-network data. No card charged until day 8. Cancel from your inbox if you decide it's not for you.
No contract. Cancel anytime.