Find out how to use your cellphone in the UK & see the best UK SIM cards for visitors and new UK residents.

If you’re visiting the UK on a short-term trip, or moving there longer-term for study or for work, it’s easy to use your cell phone on the mobile networks in the United Kingdom.

In this article, we’ll discuss cell phone compatibility on UK cellular mobile networks. We’ll also look at the different ways of using your cell phone in the UK, including through international roaming or using a local UK SIM card. Finally, we’ll compare the best value prepaid SIM cards that are available for tourists, visitors and new residents to the UK.

Best UK SIM Card: giffgaff
Recommended Plan: £10 for 15GB data & unlimited UK minutes
Inclusive Features:
  • Free international delivery: your SIM card can be sent anywhere in the world.
  • No contract, no credit check & no need to be a UK resident to sign up.
  • No need for a UK bank account: you can top-up with an international card.
  • Use your giffgaff SIM card at no extra cost in 37 European destinations.
Network Coverage: 99% UK population coverage on 2G, 3G & 4G
Compatibility: Works with most unlocked GSM smartphones (including iPhone & Android)
Free SIM Card: Get a free giffgaff SIM card →

Cell Phone & Network Compatibility

Network Frequencies & Bands

  • EE
  • O2
  • Three
  • Vodafone

In the UK, there are four companies that provide cellular mobile coverage: EE, O2, Three & Vodafone. Each of them offers around 99% population coverage across the UK using 2G (GSM), 3G (WCDMA & HSPA) and 4G (LTE) technologies. In addition, 5G coverage (NR) is available in most major UK towns and cities.

The four cellular coverage providers utilise the following bands and frequencies in the UK:

Coverage Provider 5G Bands 4G Bands 3G Frequencies 2G Frequencies
EE 5G NR Band n78 LTE bands 3, 7, 20, 1, 38 2100MHz 1800MHz
O2 5G NR Band n78 LTE bands 20, 1, 3, 8, 40 2100MHz, 900MHz 900MHz
Three 5G NR Band n78 LTE bands 3, 20, 1, 32 2100MHz
Vodafone 5G NR Band n78 LTE bands 7, 20, 1, 3, 8, 32, 38 2100MHz, 900MHz 900MHz

The most important bands for your phone to support are shown in bold. Most modern cellphones should at least support a couple of UK bands, providing you’re using a device that’s compatible with GSM or LTE. Additional bands and frequencies are shown in italics – you may get faster speeds if your phone has support for these bands.

Alongside the four cellular coverage provider, there are a number of mobile virtual network operators (MVNOs). These MVNOs “piggyback” on signal from one of four cellular coverage providers. For instance, giffgaff uses coverage from the O2 (Telefonica) network. You’ll therefore get the same coverage on a giffgaff SIM card and on a O2 SIM card.

If you’re unsure about the bands and frequencies supported on your cellphone, consult your handset manufacturer’s documentation or product specifications. For instance, you can see a list of 4G & 5G bands supported on the iPhone.

Roaming VS Using A UK SIM Card

There are two ways to use your cellphone in the UK: you can either roam on your domestic SIM card or you can use a local SIM card from a UK network.

If you’re only visiting the UK for a short amount of time, roaming on your normal domestic SIM card can sometimes be the easiest solution. In advance of your travel to the UK, you should check with your cellular provider on the costs of using your phone in the UK. You should also ensure that international roaming is enabled on your account.

If you’re planning to stay in the UK for a little bit longer, it’s normally worthwhile getting a local UK SIM card. This will probably be more convenient and will usually be cheaper than roaming on your normal domestic SIM card. In the UK, prices start from about £10 for one month’s usage on a local SIM card. This will also cover your cellphone usage when you travel to other European countries. You’ll get a UK-based phone number on your UK SIM card (starting with +44).

Getting a UK SIM Card

It’s a straightforward process getting a prepaid SIM card in the UK. There’s no need to be a UK resident, and you don’t need to provide any identification documents. You will, however, need to make sure that your cellphone is unlocked from your carrier before you arrive in the UK.

Where possible, we’d strongly recommend getting your UK SIM card before you arrive. Not only does it avoid an unnecessary trip to get your SIM card from a shop, it can save you a lot of hassle as you’ll have a SIM card that’s charged and ready-to-use. You’ll also get a wider choice of options and can normally save money by getting your SIM card in your advance.

At present, giffgaff is our recommended SIM card for anyone who is visiting or moving to the UK. Unlike most other networks, they offer international delivery for free on all of their SIM cards. You can also activate and recharge your SIM card using a credit card or debit card that’s based outside the UK. This differs from most other networks where you’ll normally need to use a UK-based card to top-up or recharge.


  • Free international delivery & top-up using international credit/debit cards.
  • £10 top-up buys: Unlimited minutes, unlimited texts and 15GB data.
  • Uses the O2 network. 99% coverage, 3G & 4G internet, check coverage here.

giffgaff is our recommended prepaid network for anyone who is visiting or moving to the UK.

They’re one of the UK’s most popular cellular network brands and they’re unique in offering free international SIM card delivery. This means you can have your SIM card packed and ready to go before you even leave for the airport. giffgaff will also allow you to top-up online using an international credit card or debit card (whereas most other networks will only accept payment cards from the UK).

On giffgaff, a £10 top-up will give you 15GB of data along with unlimited UK minutes and unlimited UK texts. You’ll also be able to use the SIM card at no extra cost in 37 European countries. International phone calls from the UK to another country are also available at a small additional cost. On giffgaff, you can use tethering and personal hotspot to share your data allowance with other devices.

For customers wanting a larger allowance of data, giffgaff offers 30GB data for £15 or 100GB data for £20. For £25, you’ll get Always-On data (unlimited downloads with the first 80GB per month at full 4G download speeds).

Order giffgaff SIM card (Free) →

giffgaff uses O2 (Telefonica) as their cellular network coverage provider. This means you can use a giffgaff SIM card in any phone that supports GSM 900, WCDMA 2100 or LTE band 20.

If you’re not able to order a SIM card from giffgaff in advance, it’s also possible to get a SIM card on arrival in the UK.

Where possible, you should avoid getting your SIM card upon arrival at the airport (e.g. when you land at Heathrow or Gatwick). Although a couple of retailers will offer UK SIM cards at the airport, they’re normally grossly overpriced. Instead, you’ll save money by waiting until you arrive in the city. You can get a UK SIM card from most cell phone stores, grocery stores and gas stations (also known as mobile phone shops, supermarkets and petrol stations in the local lingo). Compared to ordering online, you should expect to pay a couple of pounds more to get your SIM card in-person, plus £10 or £15 for your initial top-up or charge. Our full guide to prepaid SIM cards in the UK will give you a full overview of the available options.

As a word of warning, most UK networks won’t allow you to top-up online or by phone when using a payment card that’s registered outside the UK. Therefore, unless you’re on a network like giffgaff that supports international top-ups, the only way to recharge your account will be making an in-person top-up at locations showing the green “top-up” logo.

At the end of your trip to the UK, it’s worth holding on to your SIM card. Typically, your prepaid SIM card will remain active for another 6 months after the last chargeable usage on your SIM card. Therefore, if you’re planning to visit the UK again on a future trip, it might be possible to re-use your SIM card.

Note on Pay Monthly deals: If you’re moving to the UK on a longer-term basis, you may be tempted to get a Pay Monthly SIM card. Before you’re able to apply, you’ll need to be a UK resident and you’ll need to pass a UK credit check. You’ll also need a UK bank account from which your monthly Direct Debit payments can be taken. For this reason, unless you’ve already lived in the UK for a significant amount of time, we’d recommend getting a prepaid deal such as giffgaff.

Using Your Phone In Europe

If you’re combining your trip to the UK with a trip to mainland Europe, you’ll normally be able to use your UK SIM card at no extra cost in Europe. This is the case on most UK networks with the exception of EE, which is introducing European roaming charges from January 2022.

If you’re using a prepaid UK SIM card like the one from giffgaff, you’ll be able to use your allowances at no extra cost in the following European countries:

Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gibraltar, Greece, Hungary, Iceland, Israel, Italy (includes Sardinia and Sicily), Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal (includes Azores and Madeira), the Republic of Ireland, Romania, Slovakia, Slovenia, Spain (includes Canary Islands and Balearic Islands) and Sweden

Likewise, if you have a SIM card from another European country, you might be able to use it in the UK at no extra cost. However, you should check with your domestic operator to see what they’ll charge for roaming in the UK. This is because the UK is no longer covered by EU roaming legislation as of January 2021.

Other Useful Information


In the UK and Europe, the cellular industry tends to use different terminology to what is used in North American countries. Namely:

  • Cellphones are normally referred to as mobile phones in Europe.
  • Carriers or cellular networks are more commonly referred to as mobile networks.
  • Prepaid SIM cards are normally advertised as Pay As You Go SIM cards.
  • Instead of re-filling or re-charging your prepaid plan, people normally talk about topping up their Pay As You Go account.

When shopping or comparing price plans, it’s also worth knowing that taxes are already included in the price. In the UK, this mainly refers to value added tax (VAT), which is similar to sales tax in other countries.

International Dialling

If you’re using a UK SIM card, you’ll be assigned a new UK-based phone number on your SIM card. The phone number will be 11-digits long and will always start with 07 (e.g. 07123 456 789).

If your friends or family members would like to call you from outside the UK, they’ll need to replace the zero at the start of your phone number with +44. This will give your international phone number (so, for instance, 07123 456 789 becomes +44 7123 456 789).

Similarly, if you’re calling abroad from a UK SIM card, you’ll need to add the relevant international calling prefix before dialling out to that number.

Useful Resources

In the UK, the emergency services phone number is 999. This is a single phone number for all emergency services including the police, ambulance and fire service. The pan-European emergency phone number (112) will also work when you’re inside the UK.

If you’re making phone calls on a UK SIM card, your inclusive minutes will normally allow you to call other UK landline and mobile numbers (that’s most phone numbers beginning with 01, 02, 03 and 07). If you’re calling another phone number that isn’t included in this range, find out how much the phone call will cost.

If you’re looking to get connected to the internet without using a cellular data allowance, many locations now offer a free wi-fi connection (including many coffee shops, grocery stores, train stations and more). In the UK, the main providers of public wi-fi are BT, O2, Sky (The Cloud) and Virgin Media.

For getting around, it’s worth using the Transport for London (TfL) and National Rail Enquiries websites. They’re both invaluable for providing you with information on how to get around the UK (TfL covers public transport services in London whereas National Rail Enquiries covers rail travel across the rest of the UK). You can also use Google Maps for transit directions, as well as CityMapper in major urban areas.

If you’re travelling to the UK during the Coronavirus (COVID-19) outbreak, you may need to self-isolate for up to 10 days on arrival. This is unless you’re arriving from a green list country. You’ll also need to provide your journey and contact details in advance by submitting it on the GOV.UK website. Guidance and regulation is continually changing in this area so check the GOV.UK website before your trip.

Have a smooth trip and enjoy your visit to the UK!

Frequently Asked Questions

What is the best UK SIM card if you’re moving to or visiting the UK?
We’d recommend getting a prepaid SIM card from giffgaff. They offer free international delivery and you can top-up online using a bank card from any country. For £10/month, you’ll get unlimited minutes, unlimited texts and 15GB of data, with 99% UK population coverage.

If you choose a different carrier, you’ll likely need to get your SIM card in-person from a retail store in the UK. You may also need to top-up your SIM card in a store as most UK carriers will not accept online top-ups from a bank card registered outside the UK.

Will I need to be a UK resident to get a UK SIM card?
There’s no need to be a UK resident to get a prepaid SIM card like the one from giffgaff. You can order and activate the SIM card online without providing any ID or passing a UK credit check.

If you want to get a Pay Monthly contract, this will require you to be a UK resident. You’ll also need a UK bank account and will need to pass a UK credit check. For this reason, we’d always recommend starting off with a prepaid SIM card. You can change it to a Pay Monthly SIM at a later date, if you like.

Will my cellphone work in the UK?
Your cellphone should work in the UK providing it’s unlocked for use on other networks and providing it supports the following frequencies and bands:
  • For 2G coverage: GSM 900MHz or GSM 1800MHz
  • For 3G coverage: WCDMA/HSPA 2100MHz
  • For 4G coverage: LTE bands 3, 7 or 20
  • For 5G coverage: NR band n78

Your Comments 370 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 370 comments from readers. You can add your own comment here.

  • Hi,
    I will be studying abroad in the UK for a few months. So if I go with giffgaff, I will insert the SIM card once I arrive in the UK and get a new number? Once I return to the US, do I simply swap it out with my original SIM card have the same number I had before?

    • Hi Shane,
      Thanks for your comment. Yes, you’ll get a new UK-based phone number when you put the giffgaff SIM card inside your phone. You can then switch it back for your US SIM card at any time and your US phone number will come back (as the phone number is attached to the SIM).
      Hope this helps,

      • Hi Ken, really appreciated the info. Forgive me if my questions sound stupid. My question is related to the local UK number. Once I receive the giffgaff SIM card, will I see/know the UK-based phone number (on the card or somewhere in the package)? I ask because I need a phone number when I register in the Passenger Locator Form upon arriving in the UK. And I believe that number is also used for contact and trace by the NHS. So as soon as I land in Heathrow, I can just insert the sim to my iPhone and it’ll work, right? Another question is if the international free delivery applies to the £20 (100GB) and £25 (always-on) as well. Can’t thank you enough.

        • Hi Sophie,
          Thanks for your comment. Yes, the international delivery applies to the £20 and £25 goodybags as well. With regards to the phone number, I believe you’ll see it after activating your SIM card online (you can do this just before you depart, and you can then put the SIM in your phone when you arrive in the UK).
          Hope this helps,

  • Do you know if I can use an eSim card for service in the UK & Europe, keeping my USA phone number on my regular SIM card & be able to make & receive calls on either sim both on my USA number & on my new UK number. I will be an international student for 2021-2022.

  • Hi Ken, thanks for the precious info! Do you know if I can bring US unlocked phones to the UK? In the US, many carriers have a whitelist of devices they accept on their network so international phones usually do not work in the US. I wonder if this is the same in the UK. I have couple of US unlocked phones that support UK LTE bands and 3G bands, I wanna know if the UK carriers would accept them. And also, any carriers in the UK can take overseas credit card payments? Thanks! All the best 🙂

    • Hi Mister,
      Thanks for your comment. To answer your two questions:
      1) Nope, there isn’t an allowlist of devices they accept so you can simply bring a GSM-compatible phone from anywhere in the world.
      2) Yes, giffgaff will allow you to use an international credit card and they would be my recommended network. You can get a giffgaff SIM card here. There might be a couple of others that will also accept an international credit card but I believe giffgaff are the only ones that have advertised supporting this feature.
      Hope this helps,

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