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Technology·4 min read·

What is an eSIM? Everything You Need to Know

By Fuse Team

The end of the plastic SIM card

For decades, connecting a phone to a mobile network meant inserting a small plastic card — the SIM (Subscriber Identity Module). It started full-size, then shrunk to micro-SIM, then nano-SIM. Now, with eSIM, the card is gone entirely.

What is an eSIM?

An eSIM (embedded SIM) is a small chip built directly into your phone during manufacturing. Instead of inserting a physical card, your carrier sends a digital profile that's downloaded onto the chip. Think of it as a software update rather than a hardware swap.

How does eSIM work?

The process is straightforward:

  1. Your carrier provides a QR code or activation link
  2. You scan it with your phone's camera
  3. The eSIM profile downloads and installs
  4. Your phone connects to the network

The whole process typically takes less than 5 minutes.

Benefits of eSIM

Instant activation

No waiting for a SIM card in the post. Sign up and connect in minutes.

Dual SIM capability

Most eSIM phones support dual SIM — one physical and one eSIM. This means you can have two numbers or two carriers on one phone.

Better for the environment

No plastic cards, no packaging, no shipping. eSIM is the greener choice.

More space inside your phone

Without a SIM card slot, phone manufacturers have more room for battery or other components.

Is my phone compatible?

Most phones from 2018 onwards support eSIM. This includes:

  • Apple: iPhone XR/XS and later
  • Samsung: Galaxy S20 and later, Z Fold/Flip series
  • Google: Pixel 3 and later

Not sure? Use our device compatibility checker to find out.

eSIM and Fuse

Fuse takes eSIM one step further. Instead of connecting to a single network, our eSIM profiles connect to all four UK networks. Your phone automatically selects the strongest signal, giving you the best possible coverage wherever you are.

It's multi-network coverage, delivered through the convenience of eSIM technology.

Ready to get started? Learn more about why we built Fuse Mobile and our multi-network approach.

Ready to try multi-network data?

Get connected to all four UK networks in minutes.