If you’re travelling to the United States, having the right SIM card can save you a lot of money. We review the best value SIM cards for using your smartphone in the US.

USA Flag

Each year, almost 4 million Brits visit the USA. Whether you’re travelling to New York to do a bit of shopping, touring California to enjoy the beautiful scenery or visiting Florida to enjoy the theme parks with your family, you’ll probably want to use your mobile phone when you’re there.

Having a smartphone in America can make it a lot easier to stay in touch with friends and family who are back in the UK. It can also be useful for navigating around (e.g. finding nearby restaurants or attractions using Google Maps).

The good news is it’s now really easy to take a UK smartphone and to use it in the US. You can either roam on your UK SIM card or you can buy a local US SIM card upon your arrival in the States. In this article, we’ll review and compare the best SIM cards for using your smartphone in the US. We’ll also discuss network compatibility with your UK handset.

Best USA SIM Card: Three Pay As You Go
Recommended Plan: £15 for 10GB data & 3,000 minutes to UK
Inclusive Features:
  • Roam at no extra cost in the USA with your Three Pay As You Go SIM.
  • Set up & activate your SIM card in the UK, before you depart.
  • Up to 3,000 minutes of calling to the UK & each other included.
  • No contract & no credit check.
Network Coverage: 99% US population coverage
Compatibility: Works with most unlocked smartphones (including iPhone & Android)
Free SIM Card: Get a Three Pay As You Go SIM (with £15 top-up) →

Using Your Mobile Phone In The USA

If you’re planning a trip to the USA, there are two ways to use your mobile phone when you’re there:

  • You can roam on a UK-based SIM card. This is the most convenient way to use your mobile phone in the USA. You’ll have a UK-based phone number (+44) and you’ll pay your UK mobile network for usage.
  • You can buy a US-based SIM card on arrival. If you’re a frequent traveller to the US or if you need a US-based phone number, you can get a local US-based SIM. However, this is typically a more expensive option unless you regularly travel for an extended amount of time.

The following table shows a side-by-side comparison of the two options:

Roaming on your UK SIM card Buying a US SIM card on arrival
Best for one-off or occasional trips to the US.
Best for frequent travellers to the US.
You’ll have a UK-based number (beginning with +44). You’ll have a US-based number (beginning with +1).
We recommend Three’s Pay As You Go SIM (either 4GB data for £10 or 10GB data for £15). Choose a SIM from AT&T or T-Mobile USA. Prices start from $30/month (£22), plus tax and activation fees.
You’ll need to set up & activate your UK SIM card before you depart. You’ll need to buy & activate your US SIM card on arrival (e.g. at a grocery or phone store).
Will normally give you 4G speeds in the USA. May give you faster 5G speeds (subject to coverage, handset& plan compatibility).
You can continue to use your SIM card in the UK after the end of your trip. Your US SIM card will expire after 60-90 days unless you top it up again during this time.

For most people, we’d normally recommend roaming on a UK-based SIM card, unless you’re planning to travel to the USA very frequently or for an extended amount of time.

If your current mobile network doesn’t give you cheap roaming rates in the USA, getting a Pay As You Go SIM card from Three is normally the best value option. At present, you can get 4GB data for £10 or 10GB data for £15. These allowances can be used in the United States at no extra cost.

Roaming On Your UK SIM

Inclusive Roaming Deals

  • EE
  • O2
  • Three
  • Vodafone

The simplest and easiest way to use your phone in the USA is normally through international roaming on your UK-based SIM card.

As a first step, you should check to see whether your existing provider allows you to roam in the USA at no extra cost:

  • EE Pay Monthly: If you’re an EE Pay Monthly customer with the Roam Abroad Pass, you’ll be able to use your plan allowances at no extra cost when you’re travelling in the USA. This is available as one of the Smart Benefits on an EE Smart plan.
  • O2 Pay Monthly: If you’re an O2 customer, you can roam in the USA at no extra cost if you have the O2 Travel Inclusive Zone Bolt-On. This is available on selected O2 Pay Monthly plans when you also join Virgin Media as a Volt customer. For everyone else, there’s a fee of £4.99 per day for using your phone in the USA.
  • Three Pay As You Go: If you’re a Three Pay As You Go customer, you’ll be able to use your plan at no extra cost when travelling in the USA. Simply choose a Pay As You Go bundle such as 4GB data for £10 or 10GB data for £15.
  • Three Pay Monthly: If you’re a Three Pay Monthly customer, it might be possible to roam at no extra cost. This is only available on Pay Monthly plans taken on or before the 30th September 2021. On Pay Monthly plans taken since the 1st October 2022, there will be a £5 daily fee from the 23rd May 2022. This fee doesn’t apply if you’re using a Pay As You Go SIM card.
  • Vodafone Pay Monthly: If you’re a Vodafone Pay Monthly customer with Global Roaming Plus, you’ll be able to use your mobile phone at no extra cost when travelling in the USA. Otherwise, it will cost you an extra £5 per day.

Standard Roaming Rates

If your current provider doesn’t offer inclusive roaming in the USA, the following table shows the standard roaming rates you can expect to pay:

Network Making a Phone Call Receiving a Phone Call Sending a Text Accessing the Internet
BT Mobile £1.46/minute £1.30/minute 41p/text £6/day for 500MB
EE £1.25/minute £1.25/minute 62p/text £5.02/day for 500MB
giffgaff £1.00/minute £1.00/minute 30p/text 20p/MB
O2 £2.00/minute £2.00/minute 50p/text £7.20/MB
iD Mobile £1.68/minute £1.50/minute 42p/text 30p/MB
Lebara Mobile £1.49/minute £1.49/minute 49p/text £14.99/MB
SMARTY 50p/minute 5p/minute 20p/text 10p/MB
Sky Mobile £6/day to use your UK allowance of minutes, texts & data
Tesco Mobile £1.29/minute 89p/minute 40p/text £5/MB
Three Pay Monthly £5/day to use your UK allowances of minutes, texts & data (plans taken since 1st Oct 2021)
Included on plans taken on or before 30th Sept 2021
Three Pay As You Go Included Included Included Included
Virgin Mobile £2.00/minute £1.50/minute 50p/text £5/MB
Vodafone £6/day to use your UK allowance of minutes, texts & data
VOXI 60p/minute 36p/minute 8p/text 12p/MB

Comparison of roaming charges when using your UK-based SIM card in the US. The costs shown are for calling the UK and sending a text message to the UK. It’s always free to receive a text message wherever you are in the world.

Unless you have a suitable deal for roaming, the cost of international roaming in the USA can add up very quickly. This is because the average smartphone user can easily consume more than 100MB of data per day.

Three Pay As You Go Plans

If your current provider doesn’t offer low-cost international roaming, a good option is getting Three’s £15 Pay As You Go SIM.

Three’s £15 SIM card gives you 10GB of data which you can use at no extra cost when travelling in the USA. You can also use up to 3,000 minutes for calling other UK-based phone numbers. This includes other people who are travelling with you, if they’re also using a UK-based SIM.

Get 10GB data & 3,000 minutes for £15 →

Other options for Pay As You Go plans on Three include 4GB data for £10 and 12GB data for £20:

NetworkMinutesTextsDataMonthly
Cost
ThreeUnlimited
to UK
Unlimited
to UK
4GB
in UK & US
£10.00
ThreeUnlimited
to UK
Unlimited
to UK
10GB
in UK & US
£15.00
ThreeUnlimited
to UK
Unlimited
to UK
12GB
in UK & US
£20.00

With a Three Pay As You Go bundle, the inclusive minutes, texts and data can be used abroad at no extra charge when travelling in the United States.

The disadvantage of Three’s Pay As You Go SIM is that you won’t get any inclusive minutes for calling US-based phone numbers (those beginning with +1). Phone calls to a US-based phone number will cost you a hefty £1.40/minute. You can, however, side-step these charges by using Facetime, WhatApp, Skype or similar apps to make your call.

Buying A US SIM Card On Arrival

If you regularly travel to the United States for an extended amount of time, you might be better off buying a local SIM card from one of the US mobile networks. If you’re using an unlocked UK smartphone, you’ll have the option of using a SIM card from either AT&T or T-Mobile USA. Unfortunately, a Verizon SIM card won’t work on most UK-purchased phones.

You can buy a US SIM card upon your arrival in the States. Unfortunately, it isn’t possible to buy one in advance online as the US mobile networks will not ship their SIM cards to the UK. You can buy a SIM card on arrival from retailers like 7-Eleven, CVS, Target, Walgreens and Walmart. Alternatively, you can get a SIM card from an AT&T or T-Mobile retail store.

AT&T

AT&T LogoIn the US, AT&T currently operates the largest mobile network. Their network covers 99% of the US population with 4G coverage. They also offer 5G coverage in some areas.

On AT&T, you can get a prepaid plan from $30/month (approximately £22.40) plus tax. This gets you 5GB of data, unlimited US minutes and unlimited US texts. You can upgrade this to 15GB data for $40/month, unlimited 4G data for $65/month, or unlimited 5G data for $75/month.

The following table shows the Pay As You Go tariffs available from AT&T:

Network Minutes Texts Internet Monthly
Cost (USD)
Approx
Cost (GBP)
AT&T Unlimited
to US
Unlimited
to US
5GB $30.00
plus tax
£22.39
plus tax
AT&T Unlimited
to US
Unlimited
to US
15GB $40.00
plus tax
£29.86
plus tax
AT&T Unlimited
to US
Unlimited
to US
Unlimited†
4G, no hotspot
$65.00
plus tax
£48.52
plus tax
AT&T Unlimited
to US
Unlimited
to US
Unlimited††
5G, with 10GB hotspot
$75.00
plus tax
£55.98
plus tax

† On the $65/month Unlimited plan, the use of tethering and personal hotspot is not permitted. You’ll get 4G coverage and download speeds may be reduced “during times of network congestion”. Data speeds for video streaming are also capped at 1.5Mbps .
†† On the $75/month Unlimited Plus plan, you’ll get 10GB of personal hotspot included. This includes access to 4G & 5G coverage. After the first 22GB of data usage, overall download speeds may be reduced “during times of network congestion”.

The exact price you pay will depend on local tax rates (see a list of wireless tax rates for each US state).

A discount may be available on the above prices if you pay for 12 months usage in advance or if you set up AutoPay on your account. With AutoPay, your plan will be automatically renewed every month and the payment for it will be taken automatically from your card. For this reason, we wouldn’t normally recommend it for short-term visitors to the USA.

On AT&T, phone calls back to the UK will cost you $3/minute (plus tax). This is unless you pay an extra $10/month (plus tax) to get 250 international minutes for calling the UK. There’s also a $15/month International Plus package which gives you unlimited international minutes for calling the UK.

You can get an AT&T prepaid SIM card from your nearest AT&T store. Alternatively, it will cost you $9.99 plus tax at most other retailers (approximately £7.50 plus tax).

Before getting an AT&T SIM card, it’s worth checking the coverage at places where you’ll regularly visit (see AT&T’s online coverage map).

Finally, it’s worth being aware that your AT&T prepaid SIM card will be deactivated automatically if you don’t top it up again within 60 days of your previous bundle expiring. For this reason, it will only be possible to re-use the SIM card on a subsequent trip if you plan to visit the US again within a 60-day period.

T-Mobile

T-Mobile USAT-Mobile is the third-largest mobile network in the USA. It’s totally separate from the network that was previously known as T-Mobile UK (now merged into EE), and the two shouldn’t be confused with each other.

On T-Mobile, you can get a prepaid plan from $40/month (plus tax). This gives you 10GB data, along with unlimited minutes and unlimited texts within the USA. You can upgrade this to an unlimited data plan from $50/month (plus tax).

The following table shows the available prepaid plans from T-Mobile USA:

Network Minutes Texts Internet Monthly
Cost (USD)
Approx
Cost (GBP)
T-Mobile USA Unlimited
to US
Unlimited
to US
10GB $40.00
plus tax
£30.85
plus tax
T-Mobile USA Unlimited
to US
Unlimited
to US
Unlimited† $50.00
plus tax
£38.56
plus tax
T-Mobile USA Unlimited
to US
Unlimited
to US
Unlimited†† $60.00
plus tax
£46.28
plus tax

† On the $50/month Prepaid Unlimited plan, tethering and personal hotspot usage is limited to 3G speeds.
†† On the $60/month Prepaid Unlimited Plus plan, you’ll get 10GB of tethering and personal hotspot usage at 4G speeds. After this, tethering and personal hotspot usage will be limited to 3G speeds.

You can get a T-Mobile “starter kit” for a fee of $10 (approx £7.50) plus tax at any T-Mobile retail store. This starter kit consists of a new prepaid SIM card along with an instruction leaflet on how to get started. You’ll need to pay for your one-month plan on top of this.

To activate and to use a T-Mobile SIM card, your device will need to be capable of supporting VoLTE technology on the T-Mobile network (this is more commonly known as 4G Calling in the UK). To check, you can enter your device details on the T-Mobile website.

Before getting a T-Mobile USA SIM card, it’s also worth checking the coverage in places where you’re staying.

There’s a minimum charge of $3/month on all T-Mobile prepaid SIM cards. In addition, the SIM card is only valid for 90 days since the date of the last top-up. For this reason, it will only be possible to re-use your SIM card on a future trip if you keep it active by topping up at least once every 90 days.

Handset & Network Compatibility

Most smartphones sold in the UK over the past decade should work in the US without any problems.

It’s strongly recommended that you use a 4G-capable phone. This is because the 2G & 3G network switch-off has already started in the USA (this switch-off is already complete on AT&T, whereas the switch-off is still ongoing on T-Mobile). You should also use a VoLTE-capable phone for an optimum experience.

If you’re using a fairly old handset, or if your smartphone was purchased outside the UK, you should double-check to make sure your handset will work on the US networks. Your phone will need to support at least one of the following frequencies for it to work in the US:

Network Provider 5G Bands 4G Bands 3G Bands 2G Bands
AT&T NR bands n2, n5
LTE bands 2, 4, 5, 12, 14, 17, 29, 30, 66
T-Mobile NR bands n41, n71, n258, n260, n261 LTE bands 2, 4, 5, 12, 66, 71 UMTS bands 2, 4 GSM 900

You can check your handset manufacturer’s spec sheet to see a list of bands supported by your phone. You can also enter your IMEI on the T-Mobile website to see whether your handset is compatible with their network.

It isn’t normally possible to use a UK smartphone on Verizon Wireless. This is because Verizon uses a different technology for their 3G network (CDMA/EVDO) which is incompatible with most UK smartphones. Although you can technically use it on Verizon’s 4G network, they make it difficult to activate their SIM cards if you’re using a smartphone from the UK.

Other Top Tips For Travelling To The US

Portable Battery Pack

When travelling to the US, it’s also worth bearing the following things in mind:

  1. Check the latest COVID-19 regulations. You can see the latest COVID-19 health advice and regulations pertaining to your trip on the GOV.UK website.
  2. You’ll need an ESTA to fly to the US. If you’re travelling to the US by air or by sea (even if you’re only transiting through the US to another country), you’ll need to complete an online ESTA form (from the US Electronic System for Travel Authorisation). It costs $14 per person (approximately £10.50 per person) and lasts for two years. There’s more information about this on GOV.UK and on Money Saving Expert. You should always apply for your ESTA on the official website run by the US Department of Homeland Security.
  3. Make sure your electronic devices have power before boarding. There are extra security measures for travellers to the US. All electronic devices being carried in your hand luggage will need to have sufficient amounts of power for you to be able to turn them on. This includes your smartphone, tablet, laptop and e-book reader. You could be asked to switch on the device and to demonstrate its function when passing through airport security. As there are only limited charging points available at the airport, it’s probably a good idea to invest in a portable charger (prices start from around £20).
  4. Make sure you have the relevant adapters for charging your electronics. You’ll need a UK-to-US plug adapter for charging your electronic devices. Besides your mobile phone, consider whether you might need additional adapters for your laptop, hairdryer, shaver, etc.
  5. Use TSA approved locks for securing your baggage. If you’re using a lock to secure your baggage, it must be TSA approved (see Amazon.co.uk for a list of TSA approved baggage locks). If you use a non-TSA approved lock, security teams at the airport may take a bolt cutter to your lock.

Your Comments 387 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 387 comments from readers. You can add your own comment here.

    • Hi Adrian,
      Thanks for your comment. Go Roam will continue to be free for Pay As You Go customers, even after May 🙂
      Hope this helps,
      Ken

      • True, but ONLY if you became customer before 01 Oct 2021! Any new customers will be paying the £5 DAILY charge. You should make this explicit in your article.

        From 3 website: To unlock your UK allowance in Go Roam in Europe, there’s a £2 daily roaming charge. When you Go Roam Around the World, it’s £5. The daily roaming charge is triggered as soon as you use any of your plan’s allowances in a Go Roam destination and lasts for 24 hours. If you’re on Pay As You Go, or your Pay Monthly plan started before 1 October 2021, these charges won’t apply.

        • Hi George,
          Thanks for your comment. From the 23rd May 2022, Go Roam will continue to be free for:

          • Pay Monthly customers who started their plan before the 1st October 2021
          • and Pay As You Go customers, regardless of when they started their plan

          This is a case where it’s actually advantageous to sign up as a new Pay As You Go customer as you’ll be able to benefit from something that will cost £5/day for new Pay Monthly customers.
          Hope this helps,
          Ken

  • Hi Ken, you note that both the T-Mobile and ATAT sims possible to top up within 60-90 days. Can this be done from the UK?

  • Simonetta Pantarotto said:

    Thanks Ken! This page was extremely helpful to me! I am pretty untechy and went in circle to find out what is the best solution for a holiday in the US from UK. What makes your page stand out is the link of T-Mobile confirming whether one has the correct handset to support the US network coverage. Mine doesn’t! Or rather it has a limited connectivity because it is a bit old (Samsung Galaxy S7), hence, I need to re-think my plans

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