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 20GB 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.
  • 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
  • 5G coverage in 400+ UK towns & cities
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 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, n28 LTE bands 3, 7, 20, 1, 38 2100MHz 1800MHz
O2 5G NR Band n78, n28 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 providers, 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 get a local SIM card from one of the UK networks.

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 around £10 (approx 12USD) 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. Normally, you’ll also save money when you get your SIM card in 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 registered outside the UK. This differs from most other networks where you’ll normally need to use a bank card that’s registered inside the UK.


  • Free international delivery & top-up using international credit/debit cards.
  • £10 top-up buys: Unlimited minutes, unlimited texts and 20GB 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 20GB of data along with unlimited UK minutes and unlimited UK texts. You’ll also be able to use up to 5GB data at no extra cost every month in 37 European countries. International phone calls from the UK to another country are 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 35GB data for £15 or 100GB data for £20. For £25, you’ll get Always-On data (unlimited downloads with 4G & 5G speeds on the first 100GB per month).

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 an 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 payments can be taken. For this reason, unless you’ve already lived in the UK for a significant amount of time, we’d recommend starting on 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 sometimes be able to use your UK SIM card at no extra cost in Europe.

On giffgaff’s prepaid SIM card, you’ll be able to use up to 5GB data per month 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 already have a SIM card from another European country, it might be possible to use it at no extra cost in the UK. However, you should check this with your domestic operator as the UK is no longer covered by EU roaming legislation as of January 2021.

If you’re using a UK SIM card, you can check the rates for roaming in Europe.

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 and comparing 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. The phone number will be 11-digits long and will always begin 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 would become +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.

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 20GB 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 376 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 376 comments from readers. You can add your own comment here.

  • Ken, i ordered the giffgaff sim card, but did not see on the web site where I can sign up for the 20gig plan. Does it take you there when you insert the sim? Also does it include SMS and calling?


    • Hi Doug,
      Thanks for your comment. Yes, you’ll be able to choose your plan when you activate the SIM card 🙂
      Hope this helps,

  • Steven Gatting said:

    Hi folks, arriving with the family from the US for holidays in the UK. Wife says all US phone’s are locked and doesn’t really want to get ours unlocked in UK. It might seem obvious but what would be our best options , we don’t really want to but new phones in the UK which we will only need for a couple of weeks. Great website and loads of information and any more will be greatly appreciated.

  • Brian Lerohl said:

    I like most of your very valuable and well written article. Thanks for posting it. As regards compatibility, your comment “works with most unlocked smart phones” implies that it does not work with standard cell phones. Please verify whether the giffgaff sim will work with regular unlocked 2g & 3g cell phones. I have already verified telecommunication standard and frequencies match OK.
    I understand that I have to activate my sim card here in the US online before I leave for Europe. Germany has very strict activation rules for sims. Will my sim stay activated when I arrive in Germany?
    Best Regards,

    • Hi Brian,
      Thanks for your comment. Yes, a giffgaff SIM card will work in a regular 2G & 3G phone. You can order your SIM card to the US, but I believe you’ll need to use it in the UK first before you’re able to use it in Germany. As it’s a UK-based SIM, you’re not subject to Germany’s activation rules.
      Hope this helps,

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