eSIM- What is it and How to Use it?

Picture of an eSIM smartphone

An eSIM or ‘Embedded SIM’ is essentially a small hardwired chip inside your smartphone that could replace a traditional SIM card. Currently, eSIMs usually accompany traditional SIM tray slots in certain handsets.

The main pursuit of eSIM technology can be traced to way back in 2013 and credited to GSM Alliance. Initially it was a solution to the limited carrier provisioning that restricts the traditional SIM card technology. Since 2013, eSIM technology has been adopted by some of the biggest smartphone manufacturers such as Google and, of course, Apple, with it’s creatively named Apple SIM.

What are the advantages of eSIM?

The eSIM has many significant advantages over traditional SIM technology. One of the most recognised is it’s global specification by the GSMA which allows multiple remote SIM provisioning from any network, globally. There are a number of customer benefits attached to its use, such as:

  • Replacing a traditional SIM with an eSIM will, in the long term, reduce manufacturing costs for manufacturers, which may reduce handset costs to consumers.
  • Better designed devices reduce space requirements of traditional SIM cards and trays.
  • eSIM users have the freedom to avoid carrier provisioning restrictions that are associated with traditional SIM cards.
  • eSIMs allow users to switch between providers easily and with a QR code.
  • Mobile Network Providers will have the ability to attract new customers without the provisioning of a SIM card and associated manufacturing and postage costs, which are typically passed onto the customer.
  • eSIMs allow for a more diverse product range, such as smartwatches (Apple smartwatches and Samsung Gear S3 LTE to name a few) and IoT (Internet of Things) devices.

eSIM identity

When you unbox any new smartphone that has dual SIM capability, you will notice that it will have two IMEI codes on the box; the same is true for phones with one traditional SIM card slot and an eSIM.

The eSIM stores all the same identification codes as a typical sim card, including most importantly, an IMSI (International Mobile Subscriber Identity), which is used by mobile networks to decipher and identify information transmitted from the card user. This is effectively the unique code that a SIM card contains but in a chip version.

An IMEI number (International Mobile Equipment Identity) is used to uniquely identify GSM, WCDMA, and iDEN mobile phones, as well as some satellite phones.

Additionally, an eSIM has M2M (Machine to Machine) and remote provisioning capabilities which will become an industry-standard in the coming years as the technology is picked up by more and more manufacturers.

Who is using the eSIM?

Currently, the few manufacturers who are using the eSIM technology, most notably Apple, Samsung, and Sony, have incorporated the eSIM in their product ranges in a limited scope. However, as technology advances are measured in months and not years, you can expect to see more use of the eSIM in smartphones and devices by early 2020, and the phase-out of traditional SIM card use in devices by around 2025.

eSIM for travelers: Goodbye roaming charges

The ease and convenience of switching between mobile network providers without using a traditional SIM card are also very appealing to travelers, as you can simply download a new QR code that reconfigures your eSIM to a particular network. Additionally, if your phone is dual SIM compatible, you will still be able to use your existing personal phone number and SIM to make calls, receive calls and send text messages, whilst using a local network for data usage.

One of the best advantages of the eSIM is its potential to eliminate international roaming charges, allowing customers to use international roaming packages to stay connected abroad. This is feasible, and some small niche providers have started to offer ‘Global data’ packages, such as Truphone that offers a user to buy a data package that is functional in over 80 countries for a limited period of time.

Find out more about international roaming.

Can you buy a prepaid eSIM?

Currently, there are no mobile networks in the UK that offer a prepaid eSIM. You must be an existing customer on a contract, or be a business customer to order an eSIM. This, of course, will change in the coming year, as the competition within the eSIM market intensifies and mobile networks start to market to customers who buy new phones unlocked and without contracts.

There are a number of smaller niche network providers that allow you to use your eSIM and top up data when traveling. However, these are often quite expensive and restrict the amount of time you have to use data, typically from 1 day to 30 days.

Get a UK SIM deal here

eSIM: Providers in the UK

Currently, at the time of writing, EE, O2, and vodafone are the three main mobile networks in the UK with which you can use an iPhone, smartwatch, Google Pixel or other eSIM enabled devices with dual SIM functionality.

Apple has a dedicated section and info guide on its website, which notes a selection of networks internationally that support eSIM technology and is useful for users who plan to use eSIM abroad for any length of time.

It is expected that 2 billion eSIM subscriptions will be active globally by 2025.

While an estimated 20 billion SIM cards set to be activated by the end of 2025, a slow shift towards eSIM technology is expected as smartphone manufacturers embrace the technology. Then it’s only a matter of time until more mobile network providers adapt. Here is an update of the current progress for a select group of the UK’s top mobile network providers.


EE has a few small sections on its website detailing some basic information about the eSIM and using one on its network, but it’s by no means elaborate, nor easy to find. Here’s a brief summary of where EE is at with the eSIM

Devices currently using an eSIM and supported by the EE network

EE additionally provides a guide to what mobile handsets and devices are currently supported on its network an is summarised below.

  • iPhone XS
  • iPhone XS Max
  • iPhone XR
  • Google Pixel 3
  • Google Pixel 3 XL
  • Google Pixel 3a
  • Google Pixel 3aXL

The EE website also goes into detail about how to order an eSIM if you already own one of the devices above, but you must be an EE customer first before you can order. If you are already an EE customer, you can call a sales agent on any EE registered handset by dialing 150. Alternatively, you can pop into any EE store and purchase or replace an EE eSIM directly.

As there is no physical SIM, an eSIM pack contains instructions and a QR code that you scan with the camera of your phone to initiate the installation of the eSIM. It’s worth noting that in the UK that you may also need to obtain a PAC code from your existing provider first, before switching over to an EE eSIM.

Best EE SIM-Only deals for dual SIM phones

If you purchase a dual SIM device, check out these SIM-Only deals offered by EE.


Vodafone eSIM

At the time of writing, Vodafone is only supporting eSIM use on one product, the Apple smartwatch, however, this may change in the coming months.


Currently, the following devices are supported with O2 services and an eSIM, and they have noted additional new phones may be added to the list later in 2019.

  • Apple iPhone XS
  • Apple iPhone XS Max
  • Apple iPhone XR
  • Apple iPhone 11
  • Apple iPhone 11 Pro
  • Apple iPhone 11 Pro Max
  • Google Pixel 3
  • Google Pixel 3 XL

If you’re already a Pay-Monthly customer? We can help, call us on 01704 468005.

There’s also information on the O2 website regarding ordering an eSIM pack and setting it up using the QR code that is included in the pack.

Here’s a summary of key points regarding eSIM and O2 services:

  • Allows for eSIM devices to be used on the network
  • O2 5G network supports eSIM
  • Can you be an O2 Pay As You Go customer using an eSIM
  • Can O2 support business customers using eSIM
  • Can you order/download an eSIM online with O2
  • Does O2 support IOS 13 and eSIM
  • Does O2 support Android Q and Android P users with eSIM

Best O2 SIM-only deals for dual SIM phones


Three eSIM

At the time of writing, THREE does not have the available network technology to allow for the eSIM subscribers to join its network. Three’s constant backtracking of the eSIM launch date has infuriated a number of customers, who have taken to online forums and chat groups to express their disappointment.

Truphone Travel eSIM

In addition to the list of mobile networks that have already started facilitating eSIM technology, there’s also a growing number of niche providers that are offering ‘Global data packages’, which are particularly handy for dual sim phones. One example is Truphone, which is offering a ‘Global Mobile data plan’ that can be used in 88 other countries, either with 4G or at a minimum 3G capability, depending on the country.

Whilst Truphone’s eSIM coverage is impressive, the cost of data plans are somewhat expensive coming in on average at GBP 15 for 1GB of data for 30 days. Having said that, it’s a great option for a holiday or a short-break.

Truphone Global Data plans:
Data Included Time Period Price (GBP)
300Mb 1 day 6 GBP
1GB 30 days 15 GBP
3GB 30 days 42 GBP

Truphone also has a handy app, which you can download from the App Store or Google Play. The app allows you to load data plans directly to your phone, check your data usage and spend.

Will eSIM work on a 5G network?

At the time of writing, 5G is not currently compatible with eSIM technology in the UK, but don’t worry, it won’t be long before Telcos start to adapt their existing infrastructure for 5G and eSIM technology. Launched by EE early May 2019, 5G technology rollout is a fast mover, and according to the 2019 Ericsson Mobility Report, 5G will reach 1.9 billion subscriptions worldwide by 2024.

5G Network Rollout in the UK:
Network 5G launch date
EE May 2019
Vodafone July 2019
THREE August 2019
O2 October 2019

eSIM - Who is in control?

Currently, the power lies with the user of the eSIM, as there is no way for a specific provider to lock down your eSIM to one specific mobile network, meaning the user has the ability to seamlessly move from one mobile provider to another. Well, Sort of.

Actually, it’s not so much ‘power to the people’, but more so ‘power to the software engineer’. Ultimately it’s down to how your phone’s software can be configured. This is something that very much reigns true with Apple phones - Apple is effectively the gatekeeper for every part of the software that operates on any Apple device.

What countries support eSIM?

You’ll want to be careful with which countries provide support for eSIM. It being a relatively new technology, there are only a handful of countries that have fully embraced the eSIM at the time of writing.

  • Austria: t-Mobile
  • Canada: Bell
  • Croatia: Hrvatski Telekom
  • Czech Republic: T-Mobile
  • Germany: Telekom, T-Mobile
  • Hungary: Magyar Telecom
  • India: Airtel, Reliance, Jio
  • Spain: Vodafone Spain
  • United Kingdom: EE and O2
  • United States: AT&T T-Mobile USA, Verizon Wireless

Will all mobile networks use eSIM?

It’s likely just a matter of time before more and more mobile network providers adopt the eSIM specification to their existing infrastructure, but there is some resistance. In the eyes of the network provider, there are significant disadvantages in allowing a customer to freely move from one network provider to another.

Additionally, as competition becomes more intense in the local and international SIM market, it may force some providers out of the market altogether, as margins tighten up on services offered.

There are some advantages for network providers that embrace the eSIM. As IoT (Internet of Things) and more and more mobile-enabled devices enter the market and become commonplace, the number of subscriptions available will increase, which in turn increases the customer pool for providers significantly.

There is also the reduction of manufacturing costs that may benefit mobile network providers in the future. Much in the same way that phone manufacturers will eliminate costs associated with SIM trays and physical SIM compatibility, network providers will no longer have the associated costs of manufacturing a physical Nano-SIM card (and associated postage) for consumers. The customer can simply purchase an eSIM online and be emailed a QR code or activation code.

Here’s a handy guide on how to switch your mobile network provider.

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