Best SIM Cards for Using Your Smartphone in the USA

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.

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 whilst 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 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 compare the cost of using different SIM cards and will discuss network compatibility with your UK handset.

Using a UK Smartphone on US Mobile Networks

Almost all UK smartphones sold in the past decade will work in the US without any problems. Typically, you can get 3G coverage from AT&T and both 2G & 3G coverage from T-Mobile USA. On a limited selection of newer handsets, it may also be possible to get 4G coverage in the USA.

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 with the US networks. Your phone will need to support at least one of the following frequencies for it to work in the US:

• For AT&T, your handset will need to support one of the following:
  • For 2G: AT&T switched off their 2G coverage in January 2017.
  • For 3G: WCDMA/HSPA 850 or WCDMA/HSPA 1900
  • For 4G: LTE bands 2, 4, 5, 12, 14, 17, 29, 30 or 66
• For T-Mobile, your handset will need to support one of the following:
  • For 2G: GSM 1900
  • For 3G: WCDMA/HSPA 1900 or WCDMA/HSPA 1700/2100 (AWS)
  • For 4G: LTE bands 2, 4, 12, 66 or 71

You should check your manufacturer’s spec sheet to see a list of frequencies supported by your handset.

It isn’t normally possible to use a UK smartphone on Sprint or Verizon Wireless. This is because Sprint and Verizon use a different technology for their mobile networks (CDMA/EVDO) which is incompatible with most UK smartphones.

The Two Ways Of Using Your Smartphone in the US

There are two ways to use your smartphone in the US: you can either roam on a UK-based SIM card (setting it up before you go) or you can buy a new US-based SIM card upon your arrival in the States.

• Roaming on a UK-based SIM card. Through international roaming, you can use a UK-based SIM card when travelling in the US. You’ll have a UK-based phone number and will be charged for usage through your UK network. You’ll normally be able to access coverage from both AT&T and T-Mobile USA. This is our recommended option for the majority of users. For instance, with a Pay As You Go SIM card from Three UK, you can use your smartphone in the US from as little as £10 for up to one month. This comes with inclusive data and inclusive calls back to the UK (including other UK-based mobile numbers travelling abroad with you).
• Buying a new US-based SIM card on arrival. If you’d like a local phone number in the US, you can buy a US SIM card upon your arrival in the States. This can either be from AT&T or T-Mobile USA. You should expect to pay at least $40 (about £31), plus tax of 10-20% on top of that. This will give you an allowance of US minutes along with an allowance of data to use on your phone (additional charges will apply for calling back to the UK). You’ll need to buy your SIM card in person after arriving in the US (typically, you’ll also need either a US-based credit card or cash to pay for your top-up). Typically, it will only be worth getting a local US SIM card if you regularly travel there for extended amounts of time.

Roaming On Your UK SIM Card

The simplest and easiest way to use your smartphone in the US is through international roaming on your UK-based SIM card. The prices for using your mobile phone abroad in the US will vary depending on your home UK network:

Network	Making a Phone Call	Receiving a Phone Call	Sending a Text	Accessing the Internet
BT Mobile	£1.40/minute	£1.25/minute	40p/text	£5/MB
EE	£1.20/minute	£1.20/minute	60p/text	£4.80/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
Orange	£1.44/minute	£1.44/minute	60p/text	£8/MB
Plusnet Mobile	£1.30/minute	70p/minute	40p/text	£8/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
T-Mobile UK	£1.44/minute	£1.44/minute	60p/text	£4/day for 40MB
Three	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

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.

If you’re roaming on a UK-based SIM card, you can normally benefit from coverage on both AT&T and T-Mobile USA (your smartphone will automatically choose the network offering the strongest coverage).

The Best Network For Roaming in the US

Three is by far the cheapest mobile network for roaming in the US. When travelling to the United States of America, customers on Three can use their normal UK allowances at no extra charge. The offer is open to customers on both Pay Monthly and Pay As You Go. For more information, see our in-depth guide to the Go Roam offer.

If you’re not currently a customer of Three, you can benefit from the offer by ordering a Three Pay As You Go SIM card. For instance, a £10 top-up will give you unlimited minutes, unlimited texts and 4GB of data (up to 30 days usage in the US). You can upgrade this to 10GB of data for a £15 top-up or 12GB of data for a £20 top-up:

Network	Minutes	Texts	Data	Monthly Cost
	Unlimited to UK	Unlimited to UK	4GB in UK & US	£10.00
	Unlimited to UK	Unlimited to UK	10GB in UK & US	£15.00
	Unlimited 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.

Your inclusive minutes and texts can only be used for contacting other UK-based phone numbers. This includes any friends or family members who are also travelling abroad with you and using a UK-based SIM card of their own. For instance, your friends or family members could also be using a SIM card from Three. Phone calls to a US-based phone number will cost you £1.40/minute. However, it’s possible to side-step this by using a voice-over-IP application like Skype or Google Voice.

As an alternative to Go Roam, customers with a Vodafone Unlimited Max price plan will have access to Vodafone’s Global Roaming Plus with inclusive roaming in the US. O2 offers inclusive roaming in the USA on selected Pay Monthly plans with more than 10GB of data. Meanwhile, EE offers the Roam Further Pass as a swappable benefit for customers with an EE Smart Pay Monthly plan.

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 two US 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, the Sprint and Verizon mobile networks will not 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 online as the US mobile networks will not ship their SIM cards to the UK. You can buy a SIM card from retailers like 7-Eleven, CVS, Target, Walgreens and Walmart. Alternatively, you can get a SIM card from AT&T or T-Mobile retail stores.

AT&T

AT&T is the largest mobile network in the US. They’ve been established for a longer amount of time than T-Mobile USA, which gives them better overall nationwide coverage.

At the time of writing, AT&T says their mobile network covers 99% of the US population. This is through a combination of 3G and 4G coverage (their 2G network closed down in January 2017).

On AT&T, you can get a prepaid plan from $35/month plus tax. Historically, these prepaid plans have been known as “GoPhone” so you may still see this name being used in a few places.

For a typical smartphone user visiting the US, we’d recommend the $50 plan (approximately £38/month plus tax). This will give you 8GB of high-speed 4G data along with unlimited calls & unlimited texts within the US. Phone calls back to the UK will cost you 49¢/minute (38p/minute) plus tax, or you can buy the $5/month International Long Distance Package which gives you 250 minutes for calling a UK landline (approximately £4/month plus tax).

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

Network	Minutes	Texts	Internet	Monthly Cost (USD)	Approx Cost (GBP)
	Unlimited to US	Unlimited to US	1GB	$35.00 plus tax	£27.00 plus tax
	Unlimited to US	Unlimited to US	8GB	$50.00 plus tax	£38.57 plus tax
	Unlimited to US	Unlimited to US	Unlimited* no hotspot	$65.00 plus tax	£50.14 plus tax
	Unlimited to US	Unlimited to US	Unlimited† 10GB hotspot	$75.00 plus tax	£57.85 plus tax

* On the $65/month AT&T prepaid plan with unlimited data, the use of tethering and personal hotspot is not permitted. Download speeds may be reduced “during times of network congestion” and data speeds for video streaming are capped at 1.5Mbit/s .
† On the $75/month AT&T prepaid plan, you’ll get 10GB of tethering and personal hotspot usage. After the first 22GB of data usage, overall download speeds may be reduced “during times of network congestion”.

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 £8 plus tax).

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

If you’re staying in the US for an extended amount of time, you may be able to get a discount by enrolling in AT&T’s AutoPay programme. This will require you to have a registered credit card or debit card, from which payments will be taken automatically each month. You’ll get a monthly discount of $5 if you’re on the $35 plan or a monthly discount of $10 on plans costing $50/month or more. For short-term visitors, we wouldn’t recommend using the AutoPay feature as it means your AT&T SIM card will be topped up automatically each month in the future.

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

In the US, T-Mobile is the third-largest mobile network when measured in terms of number of subscribers. It is totally separate and independent from T-Mobile UK, and the two networks should not be confused with each other.

On T-Mobile, you can get a Simply Prepaid plan from $40/month. This gives you unlimited phone calls and text messages within the US along with a 10GB allowance of data. For $50/month, unlimited data is available on T-Mobile.

The following table shows available options from T-Mobile USA (prices and allowances are shown on a per-month basis):

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

* On the $50/month T-Mobile Simply Prepaid Unlimited plan, tethering and personal hotspot usage is limited to 3G speeds.
† On the $60/month T-Mobile Simply 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 USA SIM card “starter kit” for an upfront fee of $10 plus tax at any T-Mobile retail store (approximately £8 plus tax).

The exact price you’ll pay for the SIM card and bundle will depend on the local tax rates in the state where you’re staying (see a list of wireless tax rates for each US state). Before getting a T-Mobile USA SIM card, it’s also worth checking the coverage in places where you’re staying.

In the past, T-Mobile also offered a 21-day International Tourist Plan. This plan has now been discontinued, with T-Mobile pointing people towards their Ultra Mobile sub-brand instead. Ultra Mobile’s $30 Tourist SIM card comes with 1000 US minutes, unlimited US texts and 2GB of data. It’s valid for 21 days and the SIM card can be purchased from most T-Mobile retail stores. This plan can save you a little bit of money compared to T-Mobile’s $40 plan if you only need your SIM card for less than 21 days and if you can manage with just 2GB of data.

Our Recommended Deal

For the majority of visitors to the US, we’d recommend roaming on a UK-based SIM card. Three is by far the best UK mobile network from which to get a Pay As You Go SIM card. The SIM card is free and a top-up from £10 will give you up to 30 days usage over in the USA.

The following table gives a quick summary of the two options we’ve discussed in this article:

Roaming on your UK SIM card	Buying a new US SIM card on arrival
Best option for the majority of users.	Best option 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 the Pay As You Go SIM card from Three. There is no charge for this SIM card.	SIM cards are available from AT&T and T-Mobile USA. The SIM card normally costs about $10 (£8) plus tax.
Starts from £10 (including tax) for 30 days usage.	Starts from $35 (£27) plus tax for 30 days usage.
Coverage from both AT&T and T-Mobile USA.	Coverage from one network only.
Inclusive calls to UK-based phone numbers. Calls to a US phone number are £1.40/minute.	Inclusive calls to US-based phone numbers. Calls to the UK start from 49¢/minute (40p/minute) plus tax.
You can continue to use your SIM card in the UK after the end of your trip.	Your US SIM card will expire after 60-120 days unless you top it up again during this time.

On Three, you can choose from several Pay As You Go bundles, on which you’ll be able to use the Go Roam offer:

Network	Minutes	Texts	Data	Monthly Cost
	Unlimited to UK	Unlimited to UK	4GB in UK & US	£10.00
	Unlimited to UK	Unlimited to UK	10GB in UK & US	£15.00
	Unlimited to UK	Unlimited to UK	12GB in UK & US	£20.00

You’ll get the SIM card sent to your UK address so there’s one less thing to worry about when you arrive in the States. The SIM card will also work on both the AT&T and T-Mobile US networks. You’ll get a UK-based phone number and you’ll be able to use the inclusive minutes and texts to contact other UK-based numbers (this includes your friends and family who are also abroad with a UK-based number).

Customers of any UK mobile network can sign up for a SIM card from Three (all you need to do is to make sure your handset is unlocked). You can choose your bundle when ordering the SIM card. For most people, we’d recommend the £15 bundle with 10GB of data.

• US Roaming Price: £15/month for unlimited minutes, unlimited texts and 10GB of data
• Overages: 1p/MB once you’ve used 10GB
• £15 top-up buys: Up to 30 days of smartphone usage in the US

Order Three Pay As You Go SIM Card →

We would only recommend buying a local SIM card upon your arrival in the States if you’re a frequent traveller requiring a US-based phone number. Of the two possible US networks, T-Mobile tends to offer better value compared to AT&T. This makes them our recommended network for anyone choosing a US-based SIM card, as long as you’re able to get coverage from T-Mobile in the places where you’re staying.

Other Top Tips For Travelling To The US

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

1. You’ll need an ESTA to fly to the US (it costs $14 or approximately £11 per person). 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 £11 per person) and lasts for two years. There’s more information about this on GOV.UK and Money Saving Expert. You should always apply for your ESTA on the official website run by the US Department of Homeland Security.
2. Make sure your electronic devices have power before boarding. Compared to when you’re travelling to other countries, there are extra security measures for travellers to the US. All electronic devices being carried in your hand luggage 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 £12).
3. 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).
4. 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.