What is an eSIM and How Does it Work?

For years, tiny SIM cards have been a crucial element of connecting our phones to mobile networks. While essential, they’ve often proven awkward and easy to lose.

Moving to a new device or losing a SIM card can be a hassle, potentially leaving you without your phone number until a replacement arrives from your provider.

However, this common inconvenience can be a thing of the past, thanks to the growing adoption of eSIM technology. Let us explain.

What is an eSIM?

An eSIM, or ’embedded SIM’, is a digital alternative to traditional SIM cards.

Much like the way that eBooks can replace physical books, eSIMs eliminate the need for a physical card by integrating the technology directly into your device.

This means that you can activate your mobile plan digitally, skipping the need for a physical SIM altogether.

Shutterstock/Kolonko

How to choose and start using an eSIM

In the UK, carriers such as EE, O2, Vodafone and Three offer eSIM options, while in the US, you can get one through AT&T, Verizon and T-Mobile.

Some mobile virtual network operators (MVNOs), also known as piggyback networks, now provide eSIMs as well. For example, Voxi Mobile recently introduced eSIM support for new and existing customers.

If you’re unsure whether your carrier supports eSIM, most providers have online tools to help you check compatibility. Additionally, our guide to the best UK phone networks offers insights into available options.

We’ve also put together a comprehensive guide on the best eSIM plans for travel, business and home use.

Dominik Tomaszewski / Foundry

For frequent travellers, eSIM providers like Saily offer a versatile solution. Saily operates in over 150 countries and provides various flexible data plans.

These plans range from 1GB to 20GB and can be purchased for various durations, from days to weeks. With plenty of different eSIM providers, each with their own app, affordability and convenience are big advantages.

You can set up its eSIM once through an app on the App Store and Google Play, avoiding the need to reinstall a new eSIM for each country you visit.

The likes of Airalo and Nomad are good alternatives which are also worth considering.

How much does an eSIM cost?

The cost of an eSIM varies depending on the provider and your chosen plan.

Typically, eSIM plans are more cost-effective than traditional international roaming options, or even eSIM plans from big name networks.

Prices are determined by data quantities and the plan’s duration, and how many countries you need to use the eSIM in. You might choose a specific country, a regional eSIM or a global eSIM.

How does an eSIM work?

Setting up an eSIM is straightforward. Compatible phones (most modern devices now) can either come pre-configured by the carrier or require you to scan a QR code that is provided.

Scanning this code allows your device to download eSIM information directly to its chip.

Stock Foto.Touch / Shutterstock

Many dual-SIM phones also support eSIM technology, enabling you to use a physical SIM card from one provider and an eSIM from another.

This feature is especially useful for travellers or those needing coverage on multiple networks.

Which phones support eSIM?

The adoption of eSIM technology has been gradual due to delayed carrier acceptance. However, more manufacturers are now including eSIM capabilities to their devices.

Since 2022, iPhones in the US, starting with the iPhone 14 series, dropped physical SIM slots entirely. Android phones, while still offering physical SIM slots in most cases, increasingly include eSIM compatibility as well.

Some of the best phones, including models from Apple, Google, and Samsung, were early adopters of eSIM. Today, support extends to mid-range phones, such as the iPhone SE (2022), Google Pixel 8a and Samsung Galaxy A55.

eSIM functionality is also available in many of the best smartwatches, including the Apple Watch Series 9, Google Pixel Watch 2 and Samsung Galaxy Watch 6, as well as tablets and laptops.

If you want to make sure your phone or other devices (or one you might buy) has eSIM support, then check the specifications on the official manufacturer website first.

Why should you use an eSIM?

While eSIMs have some limitations compared to physical SIM cards, they offer unique benefits.

For users who frequently switch providers, eSIMs simplify the process by allowing you to change networks without waiting for a physical card to arrive.

All you need is a quick scan of the new carrier’s QR code. You also have the advtange of things like the ability for it to activate when you land in the country you are visiting.

Some, including Nomad and Airalo, offer free data, even if it’s just 1GB for a short time.

Tomek / Pixabay

Additionally, eSIMs can store multiple profiles on a single chip, letting you maintain separate plans for work, home, or travel.

However, privacy-conscious users should note that eSIMs cannot be physically removed, which might pose a risk if compromised.

Traditional SIM cards still have their uses, such as easy removal for use in basic phones during events where battery life is critical. However, the digital convenience of eSIMs often outweighs these advantages.

eSIM vs SIM cards

When comparing eSIMs to traditional SIM cards, several benefits make eSIMs a more appealing choice:

1. Convenience: eSIMs can be activated digitally, whereas physical SIM cards require you to visit a store or purchase them from vendors, which can be more costly and time-consuming.
2. Flexibility: Regular SIM cards are limited to a single carrier profile. eSIMs, however, can store multiple profiles, giving you the flexibility to switch between different plans and carriers seamlessly.
3. Remote activation: You can purchase and activate eSIM plans from the comfort of your home, whereas acquiring a physical SIM card often involves additional effort and potential risks of scams.

To learn more, see our separate article on the advantages and disadvantages of eSIMs.