eSIMs: What are they and how do they work?

If you have a phone that’s compatible with an eSIM, you might want to know what it’s all about. In this guide, we talk you through what an eSIM is, how it’s different from other SIMs, and the pros and cons of an eSIM over a standard SIM card.

What is an eSIM?

An eSIM is a small, electronic SIM card that is embedded directly into a device. You can’t remove or change one, but you actually don’t need to. You can install an eSIM onto any compatible device using a QR code, as it’s a programmable chip, and therefore completely digital.

How do they differ from traditional SIMs?

An eSIM is different to other SIM cards because it’s not a physical card that you can touch, insert into your phone, and swap. It’s embedded in the device and cannot be removed from a phone, tablet, or smartwatch.

Unlike traditional SIMs, eSIMs are reprogrammable. This makes changing networks simpler and easier, without the need for phone calls, PAC codes, and waiting times.

Because they’re preinstalled and reprogrammable, networks will not provide you with an eSIM when you join them. Instead, they’ll simply provide you with a QR code to sync the SIM with their network. 

Will eSIMs replace traditional SIMs?

In time, eSIMs may fully replace the use of physical SIM cards as technology progresses. 

They’re a digital form of SIM card so are smaller, save space, and impossible to lose or misplace.

Which phones are compatible with eSIMs?

Many of the newer, high-end phones are eSIM compatible, as well as having a slot for traditional SIM cards. This is usually referred to as dual-SIM connectivity.

If you use both slots at the same time (i.e. have a plastic SIM card and an eSIM in your phone), you could use two phone numbers on the same device. This could be handy for people who like to separate their work and personal life.

Here are some of the most popular eSIM phones on the market: 

  • Apple: From the iPhone 11 range to the newest 13 range
  • Samsung: S20 and S21 range, Galaxy Note 20 and 20 Ultra, Galaxy Z Flip and Z Fold 2
  • Google: From the Pixel 3 range to the 5 range
  • Huawei: P40 range

What are the advantages of eSIMs?

  • Quick to change network: eSIMs allow you to quickly change or join  networks. You won’t be waiting around for delivery, you can just rewrite the SIM card
  • Size: eSIMs are smaller than regular SIM cards, so they don’t take up a lot of space inside your phone. This could make room for bigger batteries or other high-tech hardware, or enable manufacturers to make their phones even thinner
  • Cheaper: eSIMs are typically cheaper for users while abroad as you can activate a local line digitally
  • Environmentally-friendly: SIM cards are made out of plastic, leading to lots of waste whenever people change networks. As eSIMs are digital and reprogrammable, over the years they’ll lead to a lot less landfill waste 
  • Embedded: It’s impossible to misplace your eSIM (unless you lose your phone!), so it’s unlikely that you’d lose your personal information

What are the disadvantages of eSIMs?

  • Networks: Not all mobile providers offer eSIM-compatible phones or plans. You might not be able to join the network you want or get the phone you want with an eSIM
  • Swapping phones: As eSIMs are embedded inside the device, swapping phones could be a little tricky, because you can’t just take the SIM card out and put it in your new device. Also, you could run into problems if you’re swapping from an eSIM-compatible phone to a phone only compatible with traditional SIMs
  • Compatibility: Similarly, not all phones are compatible with an eSIM, so you may not be able to get the exact phone you want with an eSIM

Where can I get an eSIM?

In the UK, you can currently get an eSIM from:

  • Vodafone
  • EE
  • O2
  • Three
  • BT Business

Does Asda mobile offer eSIMs?

At the moment we don’t offer eSIMs.

However, we do have an online shop where you can browse all our phones, some of which are eSIM compatible.

Further reading

If you’re interested in learning more about SIM cards, we’ve got plenty other guides to help you out:

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