What is an eSIM? How is it different from a SIM card?
Simply put, an eSIM is an electronic SIM that is designed to supersede the physical SIM card that has slotted into phones and smartphones for decades.
Unlike existing SIM cards, though, an eSIM is embedded into the device itself and cannot be removed and put in another phone or tablet.
Will eSIMs replace traditional SIM cards?
Eventually, yes. At the moment, eSIMs are being used as the second SIM card in a selection of top–end phones and tablets.
But as with so much in the smartphone world, features that are initially confined to pricier products quickly find their way into more affordable devices.
This means that within a few years, there will likely be no more SIM trays or standard SIM devices.
Which phones use eSIMs now?
Currently, all of Apple’s latest iPhones - the iPhone XS and iPhone XS Max and iPhone XR - come with an eSIM, as well as a standard SIM card.
The Google Pixel 3 and 3 XL also have eSIM support, again with a traditional SIM slot for existing SIM cards.
Apple’s iPad Pro and Apple Watch Series 3 and Series 4 use eSIMs too.
What do eSIMs mean for switching network?
This is perhaps the key advantage of eSIMs. As it stands switching networks can be fiddly and time-consuming, but eSIMs look set to change all that.
Because they are rewritable, you can essentially change networks as you please, depending on whether your carrier supports the tech.
Best of all, you can store more than one plan on an iPhone’s eSIM (although you can only use one at a time), so you can chop and change depending on where you are in the world.
The hope is that eSIMs will make switching seamless, without the usual fuss of phone calls, demands for PAC numbers and waiting for the switch to take place.
EE is offering dedicated QR codes which can be scanned to activate eSIM–based accounts.
Which networks support eSIMs?
EE offers eSIM support for the latest iPhones, as well as the new iPad Pro. Vodafone supports the latter.
Other UK networks have not announced when they will offer support, but with more phones with eSIM support expected in 2019, it won’t be long before the tech becomes standard.
What are the other advantages that eSIMs offer?
In terms of current devices, the biggest draw of eSIMs is being able to quickly add a second telephone number to go alongside that's attached to your main SIM card.
That means that you can have two phone numbers on a single device, which is very handy if you have separate business and personal lines but don’t want to lug around a second phone all the time.
Then there’s the added bonus for travellers. While cheap roaming is becoming increasingly prevalent, often it pays to have a local number if you’re in a different location for a longer period of time.
eSIMs mean you can activate a local line on your device without having to go to a local provider and arrange a price plan.
If your eSIM uses a different network to your standard SIM, you can easily switch between the two. This is especially useful if data coverage is poor on one but not the other.
On the latest iPhones, you can assign one SIM as the primary line for services like FaceTime and iMessage, while using the other as a secondary SIM for basics such as calls.
From a design perspective, eSIMs also mean that phones should become even slimmer, with no need for a SIM tray.
The chips themselves are much smaller than the cards currently used in most phones, leaving mobile manufacturers space to either trim the size of handsets or add other essentials, such as larger batteries.
Not got an eSIM phone yet, but need some help switching network anyway?
We've got you covered. Head to our one-stop guide to switching network for simple-to-follow advice.
Alternatively, input your details on our handy switching tool below and we'll walk you through the process step by step.