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 phone in the USA.

Each year, almost 4 million Brits visit the USA. Whether you’re travelling to New York to do some 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 home in the UK. It can also be useful for staying in touch with each other on your travels and for getting around (e.g. finding nearby restaurants and attractions on 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 (£26), 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

The simplest way to use your mobile phone in the USA is 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 at no extra cost in the USA:

• EE Pay Monthly: If you’re an EE Pay Monthly customer with the Roam Abroad Pass, you can use your plan allowances at no extra cost when you’re travelling in the USA (up to a maximum of 50GB per month). This is available as a Smart Benefit or as a chargeable £10 per month add-on.
• O2 Pay Monthly: If you’re an O2 Pay Monthly customer with the O2 Travel Inclusive Zone Bolt-On, you’ll be able to roam at no extra cost in the USA. This is available on selected O2 Pay Monthly plans and also when you join O2 as a Volt customer (requires Virgin Media broadband). For everyone else, there’s a fee of £6 per day to use 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 allowances at no extra cost when you travel to 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 will be the case if your Pay Monthly plan started on or before the 30th September 2021. On Pay Monthly plans that have been taken since the 1st October 2021, there’s a £5 daily fee. This fee doesn’t apply if you’re using a Three 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 £6 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	£1.59/minute	£1.42/minute	44p/text	£6/day for 500MB
EE	£1.35/minute	£1.35/minute	67p/text	£5.48/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	£2/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 costs 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 in the USA, a good option is getting Three’s £15 Pay As You Go SIM.

Three’s £15 Pay As You Go SIM 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:

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.

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 phone call instead.

If you’re looking to visit both the USA and Canada on your trip, see our guide on the best SIM cards for roaming in Canada.

Buying A US SIM Card On Arrival

If you regularly travel to the United States for an extended amount of time, it might be worth getting 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 will not work on most UK-purchased phones.

You can buy a US SIM card upon your arrival in the States 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. Unfortunately, it isn’t possible to buy a US SIM card in advance as the US mobile networks will not ship their SIM cards to the UK.

AT&T

In 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 (approximately £26) per month plus tax. This gets you 5GB of data, unlimited US minutes and unlimited US texts. You can upgrade this to 15GB data for $40 (approximately £34.60) per month or unlimited data (with restrictions on video streaming and personal hotspot) for $65 (approximately £56.20) per month, plus tax.

The following table shows the Pay As You Go plans available on AT&T:

Network	Minutes	Texts	Internet	Monthly Cost (USD)	Approx Cost (GBP)
	Unlimited to US	Unlimited to US	5GB	$30.00 plus tax	£26.00 plus tax
	Unlimited to US	Unlimited to US	15GB	$40.00 plus tax	£34.60 plus tax
	Unlimited to US	Unlimited to US	Unlimited†	$65.00 plus tax	£56.20 plus tax

† On AT&T’s $65/month Unlimited plan, video streaming is capped at 1.5Mbps (SD quality). The use of tethering and personal hotspot is not included. You’ll need to pay an extra $10/month to add a 5GB data allowance for tethering & personal hotspot.

The exact price you pay will depend on local tax rates (see a list of wireless tax rates for each US state). In addition, there’s normally a $15 activation fee for a new AT&T SIM card (this can vary depending on where you get it).

A discount may be available on the prices listed above if you pay for 12 months usage in advance or if you set up AutoPay on your account. However, this isn’t suitable for short-term visitors to the USA as your plan will be renewed automatically every month, even after you’ve left the USA.

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

You can get an AT&T prepaid SIM card from your nearest AT&T store. Before you do this, it’s worth checking the coverage available at places you’ll regularly visit in the USA (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 is the USA’s third-largest mobile network. It’s totally separate from the network that was previously known as T-Mobile UK (now part of EE), and the two networks 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 prepaid plans from T-Mobile USA:

Network	Minutes	Texts	Internet	Monthly Cost (USD)	Approx Cost (GBP)
	Unlimited to US	Unlimited to US	10GB	$40.00 plus tax	£34.60 plus tax
	Unlimited to US	Unlimited to US	Unlimited†	$50.00 plus tax	£43.30 plus tax
	Unlimited to US	Unlimited to US	Unlimited††	$60.00 plus tax	£52.00 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 high speed tethering and personal hotspot. After this, tethering and personal hotspot usage is restricted to 3G speeds.

You can get a T-Mobile “prepaid starter kit” for a fee of $10 (approx £8.60) plus tax at any T-Mobile retail store in the USA. The starter kit consists of a new prepaid SIM card, along with an instruction leaflet on how to get set up. You’ll need to pay for your one-month plan on top of this.

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

From July 2022 onwards, it’s strongly recommended that you use a mobile phone that’s compatible with 4G Calling (VoLTE) technology in the USA. In many areas, VoLTE technology is now a prerequisite if you want to make or receive phone calls in the USA (some limited 2G coverage is still available in certain places with reduced performance).

If you’re using a 4G-capable smartphone that lacks support for 4G Calling technology, it should still be possible to access the internet when you’re in the USA. You’ll also be able to use voice-over-IP apps such as WhatsApp, FaceTime and Skype to make phone calls. However, you won’t be able to make or receive phone calls on your normal UK phone number without 4G Calling support.

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	–	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

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 $21 per person (approximately £18 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 needs to be TSA approved (see Amazon.co.uk for a list of TSA approved baggage locks). If you use a non-TSA approved lock, the security teams at the airport may take a bolt cutter to your lock.

If you’re also planning to visit Canada along with the USA, see our guide on the best SIM cards for Canada.