eSIMs Explained

What an eSIM actually is

An eSIM, or embedded SIM, is a small chip soldered onto your phone's motherboard that does the same job as a plastic SIM card. Instead of inserting a card, you download your plan onto the phone as a digital profile, usually by scanning a QR code or through your network's app.

The chip is permanent. The profile on it is not. That distinction matters, because it means one phone can hold several network profiles at once and switch between them without any hardware changing.

Recent iPhones can store around eight profiles and run two of them at the same time. Support on Android varies by manufacturer and model, though two active lines is common on current flagships. Two active lines means you can hold a personal number and a work number on one handset, or keep your UK number live while using a local data plan abroad.

Which phones support eSIM

Support is now close to universal on phones sold in the UK above the budget tier, and it has been standard for several years.

• Apple has supported eSIM since the iPhone XS and XR in 2018. Every iPhone since supports it, and the iPhone 13 and later can run two active eSIMs at once.
• Samsung has supported eSIM since the Galaxy S20 range in 2020, including the Z Fold and Z Flip foldables.
• Google Pixel handsets have supported eSIM since the Pixel 3a.
• Motorola produced the first eSIM-only phone, the folding Razr, which had no SIM tray at all.

Where support is patchier is at the budget end of the market. Entry level handsets, feature phones and some older mid-range models may have no eSIM hardware, so it should not be assumed on a cheap device. If eSIM matters to you, check the individual model rather than the brand.

How to check whether your phone has eSIM

The quickest test works on any phone regardless of brand. Open the dialler and dial *#06#. Alongside the IMEI you should see an EID, a 32 digit number. If an EID appears, the phone has eSIM hardware. If it does not, it has none.

On an iPhone you can also go to Settings, then General, then About, and look for an EID entry. On Android, look under Settings, then About phone, or under the SIM settings.

This check is worth doing rather than relying on a specification sheet, because the same model can differ between regions. That point matters most when buying second hand, and is covered further down.

eSIM-only phones, and what that means in the UK

A small but growing number of handsets have no SIM tray at all. On these, an eSIM is not an option, it is the only way to get the phone working.

The clearest example is the iPhone Air, which is eSIM only in every market worldwide, including the UK. Apple removed the tray to make the handset as thin as possible, and there is no regional version with a slot.

The rest of Apple's current range behaves differently depending on where it was bought. UK models of the iPhone 17, 17 Pro and 17 Pro Max keep a nano-SIM tray alongside dual eSIM support. In the United States and a list of other countries including Canada, Japan, Mexico, the UAE and Saudi Arabia, the same models ship with no tray at all.

Android has moved more slowly in the UK. Current Samsung and Google flagships sold here retain a physical SIM tray, although Google has already removed it from the Pixel 10 series in the United States. The direction of travel across the industry is clear, but UK buyers still have the choice on most handsets.

The practical implication is simple. On a handset with no SIM tray, an eSIM is the only way to use the phone. Every network listed on Mobile Phone Finder can issue one, so this is not an obstacle for a normal UK purchase. It is worth confirming if you buy from a smaller provider, or outside official UK retail, where eSIM support is less consistent.

Which UK networks support eSIM

Every network listed on Mobile Phone Finder supports eSIM, as do most other UK providers. That is the easy part, and it is where most comparisons stop.

What varies is how you get one, and how easily you can move it to a new phone later. Some networks let you choose an eSIM as part of the order. Others issue a physical SIM first and switch you across afterwards, or ask you to contact them.

The process can also differ depending on what you are buying. A network may handle eSIM one way on a SIM-only plan and another way on a handset contract, so check the position for the type of deal you are taking rather than assuming a single answer per network. Most providers publish the process on their own support pages.

Our network pages cover the terms that differ most between providers, including roaming, contract lengths and annual price rises: Three, Vodafone, O2, Tesco Mobile, giffgaff, iD Mobile, Voxi, Talkmobile and Mozillion.

The real drawback: moving to a new phone

This is the trade-off that matters most in day to day use, and it is the opposite of what most people expect.

With a physical SIM, moving to a new handset takes seconds. Pop the tray, move the card, done. It works when the old phone is broken, out of battery, or wet, and it needs no account access and no internet connection.

With an eSIM, the transfer is a software process. On recent iPhones, Apple's eSIM Quick Transfer can move a profile between devices during setup, though it depends on your network supporting the feature. On Android, transfer support varies by manufacturer and by network. Where the feature is not supported you must request a new eSIM profile from the provider, which can take anything from a couple of minutes to a few hours.

Three situations are worth thinking about before choosing eSIM:

• You keep an old handset as a backup and swap the SIM when the main phone fails
• You lend a SIM to someone, or borrow a phone temporarily
• Your phone is damaged badly enough that you cannot access its settings

None of these are fatal, but they all become harder. If any of them describes how you use your phone, a physical SIM is still the more practical choice on a handset that offers both.

Switching networks with an eSIM

Switching provider works exactly the same way with an eSIM as with a plastic SIM. You request a PAC code from your current network, give it to your new one, and your number transfers, usually within one working day.

The one difference is at the end. Instead of waiting for a SIM card to arrive before you can start, your new network can issue the eSIM profile immediately, so the practical delay is shorter. Our guide on how to keep your number when switching covers the full process, including how to check your exit cost first without committing to anything.

An eSIM does not lock you to a network, and it does not make switching harder. If anything it makes the final step faster.

eSIM abroad: the strongest use case

Travel is where eSIM genuinely changes what is possible, because two active lines lets you separate your number from your data.

The setup most travellers use is this. Keep your UK line active as an eSIM or physical SIM so calls, texts and two-factor authentication codes still reach you. Add a local or travel eSIM as a second line and set it as your data line. Turn data roaming off on the UK line. You then pay local data rates rather than roaming charges, without losing your number.

Whether that saves money depends entirely on your network. Several providers we list include roaming allowances that make a travel eSIM unnecessary for short trips. Others charge a daily fee, which a travel eSIM can beat on a longer stay. The roaming position for each provider is set out on our network pages, and it varies more than any other tariff feature, alongside annual increases which we cover in our guide to mid-contract price rises.

Two practical points. Install a travel eSIM while still on Wi-Fi before you leave, since you will need a connection to add it. And check how much data you actually need before buying, which our guide to what is a good data allowance covers.

If a travel eSIM does suit your trip, Mozillion sells them covering a wide list of destinations, alongside the UK plans on its network page.

Buying second hand or imported: the trap

This is where eSIM causes genuine problems, and it applies to anyone buying refurbished, second hand, or from a marketplace seller.

The same model can have completely different SIM hardware depending on which country it was sold in. Two examples matter for UK buyers:

• An American iPhone 17 has no SIM tray. If you buy one and your network cannot issue an eSIM, the phone cannot be used at all.
• A mainland Chinese iPhone 17 has no eSIM support, only a physical SIM. If you buy one expecting to use eSIM, you cannot.

Neither is a fault or a fake. Both are legitimate regional variants that behave differently from the UK model, and neither difference is obvious from a listing photograph.

Before buying a handset outside official UK retail, dial *#06# on the device or ask the seller to, and confirm whether an EID appears. If you are buying SIM-free or refurbished stock, buy from a seller who states the regional variant. Our Mozillion page covers certified refurbished handsets, where the model provenance is documented rather than left to guesswork.

Is an eSIM more secure?

In one specific way, yes. A physical SIM can be removed from a stolen phone and put into another handset. An eSIM cannot, because it is soldered in place and tied to the device.

That removes one route thieves use to take over a phone number, though it does not protect against every form of account takeover. SIM swap fraud, where someone persuades a network to move your number to a SIM they control, remains possible regardless of whether the SIM is physical or embedded, because that attack targets the network account rather than the hardware.

Should you choose an eSIM?

An eSIM suits you if you want to be connected immediately rather than waiting for post, if you travel and want a local data plan alongside your UK number, if you need two numbers on one phone, or if you are buying a handset with no SIM tray and have no choice.

A physical SIM remains the better choice if you regularly move your SIM between handsets, keep a backup phone for emergencies, or are on a provider whose eSIM management requires contacting support.

On most UK handsets you do not have to decide permanently. Phones that support both let you start with one and move to the other later. When you browse mobile phones you can filter to handsets that support eSIM, and once you have a shortlist, check the network position separately, because a handset supporting eSIM and a network being able to issue one are two different things.

Frequently asked questions

Summary

An eSIM is a SIM built into the phone, activated by downloading a profile rather than inserting a card. Apple has supported eSIM since 2018, Samsung since 2020 and Google since the Pixel 3a, and every network we list supports it, though the ease of getting and moving one varies considerably. The iPhone Air is eSIM only worldwide, while UK models of the rest of the iPhone 17 range keep a physical tray. eSIM is faster to set up, better for travel, and cannot be removed from a stolen phone. Its main drawback is that moving to a new handset is a software process rather than swapping a card. Switching networks works exactly the same way with a PAC code either way.

How we put this guide together

Device support is taken from manufacturer specifications, and we have noted where the same model differs between regions, because that difference is invisible on a specification sheet and causes real problems for people buying imported or second hand handsets.

Network eSIM processes are drawn from each provider's published support information and from independent testing reported by others. These processes change as networks improve their systems, so we have described the general position rather than presenting a step by step process that may be out of date by the time you read it. We do not test activation on every network ourselves, and where a process is reported rather than verified by us, we have said so.

Sources and methodology

• Apple published specifications and regional availability information, for eSIM support from the iPhone XS onwards, dual eSIM from the iPhone 13, the eSIM-only iPhone Air, and the countries where the iPhone 17 range ships without a SIM tray
• Samsung, Google and Motorola published specifications, for eSIM support across their ranges and the removal of the SIM tray on the Pixel 10 series in the United States
• Network eSIM support information for the providers we list, for how an eSIM is ordered and whether existing customers can switch themselves. Where we have relied on independent reporting of a network process rather than the network's own page, the guide says the process has applied historically rather than stating it as current
• Independent consumer testing of UK network eSIM processes, including Which? and specialist network comparison sites, for reported differences in activation and transfer experience
• Manufacturer and industry guidance on EID identification, for the *#06# check

Network processes and device availability change regularly. Confirm eSIM support with your provider and check the specific handset before purchasing.