Which is cheaper for mobile data abroad: Roaming or a Worldwide Data SIM?

As more and more workplaces allow employees to work from anywhere in the world, and as international travel has spiked since lockdowns, the demand for flexible and affordable international mobile data solutions have grown with it.

But is it best to opt for an eSIM or a physical SIM card when abroad? And is it possible to use roaming with your existing mobile carrier while abroad and still save money? These options all have their own benefits and limitations, so let’s compare.

Can I get data abroad with my existing mobile phone deal?

If you’re on a existing tariff for your smartphone, most of the big mobile carriers in the UK will offer a way to stay connected while abroad – most notably through an add-on or “pass” that will enable international roaming at a discounted rate.

If you are planning a trip to Europe, select carriers – such as O2 and Tesco Mobile (which operates on O2’s network) – includes free EU roaming in 48 destinations, meaning customers can access their standard UK allowance without any extra charges. Smaller carriers like ASDA Mobile and Lebara also provide EU roaming with a fair usage cap (5GB and 30GB, respectively) that is built-in to their mobile deals.

Other carriers, however, will require you to purchase an add-on or pass in order to access your data while abroad.

To give you an idea of costs, below are what some of the top UK mobile carriers offer:

Vodafone

Vodafone's "Roam Further" add-on promises coverage for over 100 destinations. Daily roaming charges are split into four zones: A,B,C, and D.

Those in Zone A (ROI, Isle of Man, Iceland and Norway) will face no roaming charges under 25GB, while those in Zone B (47 destinations, most of which are in Europe and European member states) will have roaming costs of £2.42 per day.

Meanwhile, those in Zones C and D – which includes anywhere from Australia to Afghanistan, will face roaming costs of £7.39 per day. 

EE

EE offers a “Roam Abroad Pass” on its Smart Plans for a monthly cost of £25 and covers 47 European countries plus the US, Canada, and Australia. For non-European destinations, EE has a Travel Data Pass available at £8.45 per day for limited data. The pass allows you to use your standard minutes, text, and data that you already have as part of your existing UK plan.

In other words, you're paying an additional £25 to access your contracted usage while abroad.

O2

As mentioned above,O2 provides roaming in Europe for free on most plans and covers additional countries with an “Inclusive Zone” or daily “Travel” pass costing around £6 per day. This option covers destinations beyond Europe, including Australia and Mexico​.

Three

Three's "Go Roam" allows usage in 71 destinations for £5 per day outside Europe, covering popular locations like the US, Australia, and Canada.

Similar to the EE Pass, Go Roam gives you access to your UK calls, text, and data allowance, but must be renewed each day at a cost of £2 for the EU and £5 for the rest of the world.

*The above-mentioned prices are current at the time of writing (October 2024).

If you’re either planning an extensive trip to the EU and are not with a carrier that includes European roaming or are looking to head further afield and for a period of longer than a few days, using an add-on to access your data can quickly make your existing contract very expensive.

For this reason, and for those who require extensive, continuous global data coverage, a third-party worldwide data SIM or eSIM may be more practical, as the above plans, while convenient, are primarily designed to offer limited daily or monthly roaming at additional costs.

What is a Worldwide data SIM?

A Worldwide Data SIM is a SIM card designed to provide mobile internet access across multiple countries and regions, enabling users to stay connected while traveling internationally, all without needing a separate local SIM card or accruing costly roaming charges from home carriers.

These SIMs typically support data use in a wide range of countries, with many plans covering over 100 countries globally, and are usually offered on a pre-paid or PAYG (Pay As You Go) basis, meaning you do not need to worry about being locked into a contract.

Is a Worldwide Data SIM a physical SIM card?

Not always. A Worldwide Data SIM can be either a physical SIM card, meaning you will need to swap out your existing SIM card that is tied to your carrier in the UK and replace it with the Worldwide Data SIM when travelling, or it can be digital (known as an “eSIM”).

Physical vs. Digital SIM cards: what’s the difference?

Worldwide data SIMs come in both physical and digital (eSIM) formats:

Physical SIM Cards

These are traditional SIM cards that you insert into your phone, often available in all sizes (nano, micro, standard) for compatibility.

Generally speaking, almost all phones have a slot for a SIM card, meaning the ability to opt for a physical Worldwide Data SIM card is available to the majority of travellers. The downside is that you will need to take out your existing SIM card in order to use it, which can be inconvenient. And, if you lose your UK SIM card, it can be difficult to replace, especially whilst abroad.

Digital eSIMs

An eSIM, or embedded SIM is a digital version of a physical SIM card, but instead of physically inserting the chip into your phone, you can download access to a mobile carrier’s cellular network digitally to your device. It also enables you to have multiple lines on a device, that you can switch between.

Many newer smartphones now support eSIMs, which allow users to download a SIM profile directly to their device. This format is convenient as it can be downloaded instantly via an app or QR code, making it especially helpful when users are already abroad and need quick access to data.

You can have multiple eSIMs in your smartphone or device at once, all the while your physical SIM card remains inside your phone, allowing you to switch between various networks and providers more seamlessly.

Do UK mobile carriers offer eSIMs for travelling abroad?

While the majority of UK mobile carriers offer eSIMs, these are usually only as a replacement for a physical SIM card, and add-ons like mentioned above will still need to be purchased in order to access data abroad.

Most commonly, Worldwide Data SIMs – both physical and digital – are offered through third-party companies such as Airalo and Holafly, who specialise in offering global data SIMs.

Depending on where you’re travelling and for how long, opting for a Worldwide Data SIM can often be far cheaper than using a roaming add-on with your existing UK mobile contract.

How much will it cost me for a Worldwide Data SIM?

Exactly how much you’ll pay for a worldwide data SIM will depend largely on where you intend to travel and how much data you’ll need. But to give you an idea, the table below shows the prices from the biggest eSim providers for the USA and Australia for 10GB of data for 30 days.

Please bear in mind that these plans do not include any allowance for calls or texts. However, installing and making use of apps such as Whatsapp, Signal, or LINE will allow you to make calls and send messages using your data allowance.

Some of the above-mentioned providers only offer a connection to one or two networks (e.g. Airalo offers a network connection to the T-mobile or Verizon networks for the USA and Telstra in Australia). For this reason, the quality and speed of your connection may vary, even if you opt for a high data or unlimited usage plan.

Which devices are compatible with eSIMs?

Most Apple iPhones from 2018 onwards, as well as most Android models – such as Google Pixel devices and the Samsung Galaxy series - will be compatible with eSIMs.

If you’re unsure of the make and model of your device, you can check whether it is compatible by dialling *#06#. If you get a pop-up that includes an EID number on the screen, it means your device should work with an eSIM.

How do I use an eSIM?

It’s not uncommon to hear stories of people travelling abroad thinking they’ve switched off their mobile data only to be hit with an exorbitant bill on their return home for having unwittingly used roaming on their phone.

So, it's important to remember that if you opt for an eSIM, it will first need to be activated before you can use it. This can usually be done in one of two ways:

Scanning a QR code: Once you’ve purchased your eSIM online, you should receive a QR code that, when scanned, will request a confirmation code. This code will be provided to you by your eSIM provider once your purchase has been processed.

Activation via app: Some select eSim providers will offer activation via an app. Once downloaded from the Google Play or iPhone App store, use the instructions provided to activate the service.