Skip to content

eSIM Reviews

What is an eSIM?

July 15, 2020

Everything You Need to Know About eSIMs

For the last 30 years or so, our mobile phones have connected to networks using tiny plastic SIM cards. SIM stands for “Subscriber Identification Module”.

You’ve probably noticed the tiny electronic chip embedded into your SIM card when you’ve swapped mobile phone contracts or purchased a new handset.

That chip is actually a tiny computer containing identifiers and encryption keys and gives your handset the information it requires to connect to your chosen network provider.

Traditional SIM Cards are on Borrowed Time…

SIM cards have generally worked well up until now. It’s trivially easy to pop a new SIM card into your phone when required and connecting to a new network usually happens without a single hitch. So why change the technology if works so well?

The overriding reason for ditching traditional SIM cards is modern smartphone design: Our phones are getting thinner and more technologically advanced by the year. That means there’s less room inside your phone for a SIM card tray and all the other associated parts required to house it.

There are plenty of other reasons to ditch traditional SIM cards besides aesthetics as well:

  • Removing the SIM card slot from a smartphone improves waterproofing.
  • SIM cards are inefficient: They need to be manually posted when you change contracts or providers.
  • Swapping SIM cards can be a fiddly process. They’re also easy to break and even easier to lose.
  • SIM cards create unnecessary waste and are a bad use of resources: Providers need to manufacture huge quantities of new SIM chips each year, and chip manufacturers need to ship them all over the world.

Overall then, the SIM card was a fantastic invention in its heyday, but its creators didn’t ever envisage the massive growth of the smartphone and the rise of always-on mobile data plans.

Enter the eSIM

The future of the SIM card chip lies with the eSIM, or “embedded SIM”.

The eSIM takes the tiny chip from the standard plastic SIM card and embeds it onto the circuitry of the smartphone itself.

eSIMs are rewritable. That means if you decide to swap networks or contracts, or buy a new smartphone, you can instantly swap the information on the chip and be back up and running in seconds.

No SIM card slots, no waiting around for a SIM to arrive in the post. Zero hassle.

Are There Other Advantages?

Absolutely. We’re still in the early stages of eSIM adoption at present, and not every handset supports the new technology. In time though, it’s easy to see how eSIMs could give enormous advantages over regular SIM cards:

  • Travellers could easily swap network settings when abroad to take advantage of local data plans. No more worries about excessive roaming charges.
  • In the future, it might become possible to have 3-4 phone numbers on a single handset, or mix and match data from one provider, with minutes and text messages from another.
  • Once eSIMs become more commonplace, we might see them being adopted in laptops and even home appliances, bringing 5G connectivity to every part of the home.
  • The speed at which eSIMs facilitate swapping network providers could eventually lead to a drop in costs, as providers compete for the best deals.

Surely There are Downsides Too?

As a technology, the eSIM has literally zero drawbacks. In practice, we’re still in the early stages of eSIM adoption, and there are concerns that eSIMs could be taken advantage of by greedy corporations.

For example, in the UK, iPhones only accept eSIM network settings from the EE and O2 (and a couple of smaller startup providers). If networks and smartphone manufacturers continue to work like this in the future, we could actually see a reduction in choice, with devices being locked down to specific networks. In theory, though, this type of network monopoly won’t be allowed to continue long term.

Which Networks Allow eSIMs Right Now?

In the UK, the following providers allow the use of eSIMs on their networks:

  • EE
  • o2
  • Vodafone
  • Truphone
  • Ubigi

Carriers like GiffGaff and Plusnet actually piggyback their services from the larger providers, and at present don’t offer eSIMS with their plans.

Are eSIM Phones Future Proof?

In short, yes.

eSIM implementation has to adhere to global standard. Going forward, all smartphone eSIM chips will effectively be identical in operation. If a phone has the ability to accept an eSIM, it will continue working for the life of the device.

Is it Tricky to Set up an eSIM?

Absolutely not!

If you’re worried that setting up an eSIM will entail inputting technical network information into your phone, rest assured that the process ought to be just as fast (and simple) as inserting a regular plastic SIM. The majority of network providers can be installed on an eSIM by simply scanning a QR code using your smartphone’s camera, so in theory, you could be up and running in a few seconds.

What About Dual SIM Phones?

For business users in particular, a dual SIM phone can be a real convenience. Dual SIM phones allow two SIM cards to be inserted in a single handset, with both phone numbers being active simultaneously.

eSIM adoption shouldn’t change this feature, and in theory could make the process even easier.

Currently, we’re in the “in-between” phase of eSIM adoption, with many of the flagship handsets offering an eSIM as well as a traditional SIM card tray. For practical purposes then, that means business users shouldn’t have to return to using a second handset, so long as they configure their phone’s internal eSIM using one of the approved providers.

The advantage of having a dual SIM phone with both traditional SIM and eSIM is that users are able to store multiple network settings on the eSIM for different situations (traveling abroad etc.) whilst keeping their traditional SIM active at the same time.

In the future, we may begin to see flagship devices dropping SIM slots entirely and having several internal eSIM chips to run multiple networks at the same time.

In Conclusion…

It’s still early days for the eSIM, but with the advent of 5G technology and our heavy reliance on smartphones, one thing is for sure, the plastic SIM card that we’re all used to using is rapidly becoming a thing of the past.


This site helps you understand eSIM technology and how to use it