International SIM Card vs Travel eSIM: Which Is Best for UK Travellers?

An international SIM card (also sold as a global SIM card or worldwide SIM card) is one physical SIM that works in many countries, usually posted to you before you travel. A travel eSIM does the same job for mobile data, but you download it to your phone in minutes, with nothing to post and no need to take your UK SIM out. If your phone supports eSIM and is unlocked, a travel eSIM is usually the quicker and simpler choice. If it does not, a physical international SIM still makes sense.

Last checked: 27 October 2026. Prices and coverage change, so check the plan page and your own network's roaming terms before you book.

What is an international SIM card?

When people search for an international phone SIM, a worldwide SIM card in the UK or a global SIM for UK travellers, they usually mean a plastic SIM card that is designed to roam. Instead of buying a local SIM in every country, you put one card in your phone and it connects to partner networks wherever you go. They are often sold online and sent by post, so you need to order a few days before you leave.

The details vary from seller to seller, so read the small print. Things to check include:

• The phone number. Many international SIM cards come with their own number, often from a network outside the UK. That means a new number to share, and people calling it from the UK may pay international rates.
• Calls and texts. Some cards include calls and texts as well as data, which can be useful if you need to phone hotels or taxis. Rates often differ by country.
• Data rates by country. A card that is cheap in Europe can be expensive further afield. Look for the rate in each country you plan to visit, not just the headline price.
• Top-ups and expiry. Many work on a top-up basis, and some expire if you do not use or top up the card for a while.
• Delivery time. If the card has not arrived before you fly, it cannot help you.

What is a travel eSIM?

A travel eSIM is a data plan you download to the eSIM chip already built into most recent phones. You buy it online, scan a QR code or tap an install link, and the plan sits alongside your UK SIM. When you land, you switch mobile data to the travel eSIM and keep your UK line on for calls and texts, including bank security codes. Our guide to what an eSIM is and how it works covers the technology in more detail.

Travel eSIMs are data only. They do not give you a new phone number, and you do not need one for most trips: WhatsApp, FaceTime and other apps carry on working over data, using your existing UK number.

International SIM card vs travel eSIM: side by side

When a physical international SIM still makes sense

A travel eSIM is not the right answer for everyone. A physical SIM card is still the better choice if:

• Your phone does not support eSIM. Some older and cheaper phones only take a plastic SIM. Dial *#06#: if you see an EID number, your phone has eSIM. You can also use our device compatibility checker or read is my phone compatible with eSIM?
• Your phone is locked to a network. A locked phone will reject any other network's SIM or eSIM. Ofcom banned UK networks from selling locked phones to consumers from 17 December 2021, but older handsets and phones bought elsewhere can still be locked. Ask your network to unlock it before you travel. A locked phone also rules out most international SIM cards, so unlocking is the first step either way.
• You need a separate number with calls included. If you want a number that people abroad can ring cheaply, a SIM with calls may suit you better than a data-only plan.
• You want to pass one card between devices. For example, moving it from a phone to a portable router.

Why most UK travellers now choose a travel eSIM

For a holiday or business trip on a recent iPhone, Samsung Galaxy or Google Pixel, an eSIM avoids the main hassles of a posted SIM card:

• No waiting for the post. You can buy and install it the evening before you fly. See when to install a travel eSIM.
• Your UK number stays live. Texts from your bank and calls from home still reach your UK SIM. Turn off data roaming on the UK line so it does not run up roaming charges.
• No SIM tool and no tiny card to lose in a hotel room or on a plane.
• A plan for the trip you are taking. Pick a single country, a region such as Europe, or a global plan, and buy only the data you need.

If you are unsure how much data to buy, our guide to how much mobile data you need for a week abroad gives realistic figures.

SimplySIM global and regional plans

If you were looking for a global SIM card because your trip covers several continents, a global eSIM does the same job without the post. On 27 October 2026, SimplySIM plans included:

If your trip stays within Europe, a regional plan usually works out cheaper than a global one. For example, the Europe 10GB 30 Days plan covers 34 countries and areas and was £14.99 on 27 October 2026. Browse all regional and global eSIMs, or read our guide to global eSIMs for worldwide travel for how to choose between global, regional and single-country plans.

Is there an international SIM card with unlimited data?

Some physical SIM cards and travel eSIMs are sold as unlimited, but most have a fair use policy or a daily high-speed allowance, after which speeds drop. SimplySIM's unlimited plans, for example, give 1GB a day at high speed. Read the terms before you buy, and see our unlimited data eSIM guide for what "unlimited" means in practice.

Before you choose

• Check whether your phone supports eSIM and is unlocked.
• List every country on your trip, including stopovers, and check each is covered.
• Check your UK network's roaming terms. Some plans include Europe, while others charge a daily fee. Our guide to UK roaming charges in 2026 explains the main networks.
• Decide whether you really need a new number. For most trips, data plus WhatsApp is enough.

FAQs

What is the best international SIM card for UK travellers?

It depends on your phone. If it supports eSIM and is unlocked, a travel eSIM is usually the simplest option because you can install it in minutes and keep your UK SIM in. If your phone only takes a physical SIM, choose a card that covers every country on your trip and check the rates for each one.

Is a global SIM card better than an eSIM?

Not usually, for data. Both connect to local partner networks, so coverage is similar. A physical card is better only if your phone has no eSIM, or if you need a separate number with calls included.

Do I need a SIM card for international travel?

No. You can use your UK SIM with roaming, buy a local SIM when you arrive, or use a travel eSIM. Many travellers keep their UK SIM for texts and use a travel eSIM for data to avoid roaming charges.

Will an international SIM card change my phone number?

Often, yes. Many physical international SIM cards come with a new number. A travel eSIM does not change your number, because it is data only and your UK SIM stays active alongside it.

Can I use a travel eSIM and my UK SIM at the same time?

Yes, on dual SIM phones, which includes most recent iPhones, Pixels and Samsung Galaxy phones. Set the travel eSIM for mobile data and keep the UK line on for calls and texts, with data roaming switched off.