What is the Best UK International SIM Card?

What is the Best UK International SIM Card?

There are many different options to choose from when it comes to finding the best international SIM card. With so many choices, it can be overwhelming trying to figure out which one is right for you. In this guide, we will discuss some of the top factors to consider when selecting a UK international SIM card and offer recommendations on the best ones available.



How does international roaming work?

International roaming allows you to use your phone and make calls, send texts, and use data while traveling outside of your home country. When you travel to a foreign country, your phone will automatically connect your mobile phone to a local mobile network via a partnering agreement with your home carrier. This is where using your existing SIM card can save you money.

How do fair usage policies affect roaming charges?

A Fair Usage Policy (FUP) is a set of guidelines implemented by mobile network providers to ensure that all users have equitable and reasonable access to network resources, specifically data services. It is designed to prevent excessive use of data by a small number of users, which can affect the quality of service for other users. Under a FUP, mobile network providers may limit the speed of data services after a certain amount of data usage, or impose additional charges for usage beyond the specified limit. Therefore, when choosing an international SIM card, it is crucial to understand the provider's FUP to avoid unexpected charges or reduced data speeds.

Many international SIM cards have fair usage policies in place to regulate your data limit and the amount of calls, and texts that can be used while roaming. This is important to consider as exceeding these limits could result in additional charges or even suspension of service. It's crucial to review these policies before making a decision on which international SIM card to purchase.

Which UK mobile networks have inclusive roaming?

Many UK international SIM cards offer inclusive roaming, meaning that you can use your phone in other countries without incurring additional charges. Some mobile networks charge you for each day, whereas others have inclusive EU roaming. However, it's worth noting that none have inclusive worldwide roaming.

Nevertheless, here is a international SIM card comparison of the biggest network providers' SIM cards to hopefully help you find the top international SIM cards for your needs.

  • Three mobile: This network offers free roaming in over 70 countries worldwide, including popular destinations such as the US, Australia, and many European countries. They offer a range of SIM only deals and prepaid SIM cards if you need a SIM only for a short period.
  • EE: With EE's Roam Abroad feature, you can enjoy free roaming in over 50 destinations at no extra cost. They often have new SIM deals every month so you could find a great roaming SIM on the cheap.
  • O2: O2 offers free roaming in 75 countries with their Roam Like Home plan. They also offer unlimited calls back to the UK for free, although this does not include incoming calls coming back from the UK
  • Vodafone: Vodafone's Global Roaming allows you to use your mobile phone abroad in their inclusive roaming zone, which is over 110 destinations without additional charges.
  • Tesco Mobile: Tesco Mobile offers free roaming in 48 European countries with their Home from Home feature. However, Tesco Mobile uses the O2 network, as well as their partner networks, meaning that you could potentially find a better deal on a data SIM card on O2.
  • Sky Mobile: Sky mobile offers roaming in 36 European countries with their Roaming Passport feature. However the passport is essentially a £2 charge each day, so Sky has substantial roaming costs and is not recommended.
  • ID Mobile: ID mobile offers free roaming in 50 European countries with their inclusive EU roaming plan. However the inclusive EU roaming plan offers far less countries than other networks, like Vodafone, and has more restrictive data plans.
  • Lebara Mobile: Lebara offers free roaming in 50 European countries with their international SIM card, as well as competitive rates for calls to other international destinations. They also offer add-ons for countries outside of Europe.
  • GiffGaff: GiffGaff's Roaming Passes allow you to use your phone in over 70 destinations with no additional charges. They also offer a wide range of flexible plans, including pay as you go options.
  • Lycamobile: Lycamobile's international SIM card offers free roaming in 18 countries and competitive rates for calls to other international destinations. They also offer add-ons for data and calls to other countries.

Do any mobile networks offer unlimited data plans or a data only service while roaming?

Yes, some mobile networks do offer unlimited data plans while roaming. However all of these services will not be included in the base price of your plan, and will require additional roaming costs each day you surpass the data cap of your base plan. One example is Three Mobile's Go Roam plan, which offers unlimited data in over 70 countries for an additional fee of £2 a day when data roaming in Europe, and £5 a day when roaming globally.

However we were unable to find a data-only service for roaming on sale from any major UK network providers, but they may be available in other countries.

Can I buy an ESIM instead of having to buy a new physical SIM card?

An eSIM, or electronic SIM, is a digital SIM card that eliminates the need for a physical SIM card. It's embedded in your device and can be programmed to choose a network operator of your preference. This technology enables devices to switch between different network operators without the need to physically replace the SIM card, offering flexibility and convenience, especially for frequent travellers. Furthermore, eSIM technology is particularly beneficial for devices with limited space for a physical SIM card, such as smartwatches, tablets, and other IoT devices.

Currently, only the major networks (EE, O2, Three and Vodafone) offer eSIM support for compatible devices. A few smaller companies, such as Virgin Mobile and Lycamobile, also support eSIMs but these are in the minority.



Do I need to get a separate SIM Card or mobile phone to have international roaming?

No, you do not necessarily need to get a separate SIM card or mobile phone to have international roaming. Many networks offer plans that allow for inclusive roaming without the need for an additional SIM card.

However, if your current network does not offer this feature or has high rates for international usage, or if you need a local phone number then it may be worth considering buying local SIM cards. It might be best to buy a Pay as You Go SIM card or find SIM only deals in the country you are travelling to, however if you're travelling somewhere with a foreign language, make sure that you pick the right local SIM cards otherwise you might get saddled with a contract with a significant monthly cost rather than a prepaid SIM card!

Will I have the same mobile data allowance when travelling abroad as I do in the UK?

This will depend on the specific SIM card and network you choose. Some mobile networks may offer the same data allowance as your UK allowance when travelling abroad, while others may have different limitations or charges for international usage.

Usually you will have a fair use limit on the amount of data you can use abroad before incurring additional charges. It's important to check with your network provider before traveling to understand what your entire data allowance will be while abroad.

All network providers in the UK have a fair use data cap / data limit when roaming. These amounts will often be less than your UK SIM allowance.

Is it easier to get a local SIM card when I'm abroad instead?

Buying a local prepaid SIM card when abroad can be a more cost-effective option, especially if you plan on staying in a country for an extended period of time. There is no need for buying a separate data roaming package if you've purchased it from local mobile networks,

However, this option may not be feasible for short trips or if you need to keep your current phone number.

Additionally, purchasing a local SIM card may require additional setup and potential language barriers if you're not familiar with the country. Furthermore you might not be able to use your mobile phone when you're away abroad if it is locked to a specific carrier.

Which is the best roaming SIM card I can buy in the UK then?

After considering the factors mentioned above, it ultimately depends on your specific needs and preferences. However, based on coverage, cost, and additional features, we think the best international SIM cards are:

  1. Vodafone: Because of the ability to use your SIM in multiple countries (110) without extra charges, which is far more than any other UK network provider. These are truly global SIM cards, and also have a reasonable data allowance. The number of established partner networks they have makes it the best roaming SIM in our view.
  2. Three mobile: If you need genuinely a unlimited data allowance, then the Roam Away bolt-on will be exceptionally useful for you, and only activates when you need it. You can also find some of the best SIM only deals on their website.
  3. O2: If you want to make unlimited calls back to the UK either for business or pleasure, it would probably be wiser to go with O2 since this service is included in the base price. however it is worth noting that this does not include free incoming calls from the UK.


    In conclusion, selecting the best SIM card for international travel from the UK depends greatly on your specific needs and usage. Vodafone stands out for its broad international coverage without extra charges, making it a great choice for global travelers. Three Mobile is an excellent option for those who require unlimited data, and O2 is the best choice for those who need to make unlimited calls back to the UK. Always ensure to check the details of your data allowance, potential additional charges, and the specific benefits of each network provider before making your decision. Safe and connected travels!



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