It seems certain that future smartphones will adopt electronic SIM cards - essentially removing the need to have a physical SIM card (and SIM slot).
Quite when phones will move completely across to the new format is anyone's guess, but we may see the first devices ditching traditional SIM cards in 2020.
California based Apple has turned to eSIM to add connectivity to the new iPad Pro, Apple Watch Series 3 and Watch Series 4 as well as dual SIM support for the new iPhone XS and XS Max. After not being available at launch, eSIM for iPhone has now been enabled in iOS 12.1.
Google's Pixel 2 also supported eSIM but it was originally only used in the US for Google's Project Fi. The Pixel 3 and Pixel 3 XL do as well and - just as with iPhone - networks will roll out support for it as they launch eSIM.
The use of eSIM brings a number of advantages to device manufacturers and networks, but there's also some advantages for you, too. You could use one number for business and another number for personal calls or have a data roaming SIM for use in another country. You could even have totally separate voice and data plans.
But what exactly is an eSIM? And what exactly will it offer if your next device supports it? Let us explain more.
What is an eSIM?
The term "eSIM" simply means an embedded SIM card. There are no physical SIM cards involved and no physical swapping over required by you.
eSIM needs to be supported by the network or carrier and enabled by them and not all networks supoort eSIM as yet (see below). Note that there is also a physical SIM slot in the XR, XS and XS Max as well as the Pixel phones - the eSIM inside these handsets is used for the second SIM support.
The information on an eSIM is rewritable, meaning you can decide to change operator with a simple phone call. They're really easy to add to a data plan – connecting devices with eSIMs to a mobile account can be done in minutes.
eSIM is backed by the GSMA, the association of mobile networks. The GSMA has defined the standard for eSIM worldwide.
When is eSIM coming?
eSIM is already available from some carriers. With iPhone XS and XS Max you'll either need to have a carrier's app or a QR Code you can scan. Again, the carrier will need to support eSIM.
In the UK, EE and Vodafone support eSIM. With EE you can get a traditional SIM pack from a store (pictured here) which contains instructions and a QR code enabling your device to pick up the details. Each eSIM pack will come with its own number just like a traditional SIM pack.
Away from the traditional carriers, "global mobile network" Truphone has started selling eSIM data plans. These are able to be bought via the MyTruphone app. Truphone's international plans work across 80 countries including in Europe, the Americas and Australasia.
eSIM is great for regular travellers
Theoretically, eSIM should mean that you could go to another country and simply add a roaming eSIM to your handset while retaining access to your main "home" number. That's one of the disadvantages currently because, if you change SIMs abroad, for example, you can't access your own number.
“eSIMs have the potential to eliminate roaming charges abroad", says Truphone's Steve Alder. "It also enables people to switch operators quickly to get connected if they’re in an area with no signal, frees up space for new features or additional battery life and could lower the risk of device theft.
"As consumers and operators begin to see the benefits, mass adoption of eSIMs will be inevitable.”
What does eSIM mean for devices?
One of the advantages it offers phone makers is that we should get smaller devices because there's no need to accommodate a SIM card or the tray that holds it. There's also no need for networks to a manufacture or distribute lots of SIM cards.
eSIMs will also be great for other devices like laptops and tablets, where seamless connectivity will become the norm.
Vodafone says that eSIMs will enable more connected devices simply because eSIMs don't require so much room inside a device, enabling fitness trackers or even glasses to have stand-alone 4G connectivity in a way they just weren't able to before.
How will eSIM work in practice?
We spoke to EE to ask how it will work with eSIM. The network told us that if you have a physical and eSIM provisioned and are connected to two separate networks, your iPhone will display both networks on the screen at the same time.
If the handset is in standby and both the SIM and eSIM are provisioned, customers will be able to receive calls and texts on both numbers. As you can see in the instructions below, you can then choose a “default” line that you make calls on, use SMS and that iMessage and FaceTime use. The other line is just for SMS and voice.
Alternatively you can choose to Use Secondary for cellular data only - useful if you're abroad and using a local data eSIM.
You can store more than one eSIM in your iPhone, but you can use only one at a time.
You can switch eSIMs by tapping Settings > Cellular > Cellular Plans and tapping the plan you want to use. If you are in the UK it's Mobile Data. Then tap Turn On This Line.
How to use eSIM with iPhone XR, XS and XS Max
If you have a QR code:
1. Go to Settings > Cellular.
2. Tap Add Cellular Plan.
3. Use your iPhone to scan the QR code that your carrier provided - you may be asked to enter an activation code.
Here's what the inside of the EE eSIM pack looks like (obviously we have blurred out the QR code):
Alternatiely, you might be asked to activate your eSIM with a carrier app:
1. Go to the App Store and download your carrier's app.
2. Use the app to purchase a cellular plan.
3. You'll then Add the Data Plan to your iPhone's settings - see how that works below.
Here's how it works in the Truphone app - select the plan you want and pay using Apple Pay. The phone's Settings app will then pick up the plan so you'll need to tap Add data plan.
You should also label your plans in Settings > Cellular. Tap the number whose label you want to change. Then tap Cellular Plan Label and select a new label or enter a custom label.