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 (UK-based SIM)
Recommended Plan:	£10 for 30 days usage in the USA (up to 12GB data, 3000 minutes & 3000 texts to UK)
Inclusive Features:	Roam at no extra cost with a Three Pay As You Go SIM in the USA. Set up & activate your SIM card in the UK, before you depart. Up to 3,000 minutes for calling the UK & each other when abroad. No contract & no credit check required.
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 card →
eSIM Alternative:	US$11 (~£8.10) for 3GB data on Airalo (data only plan, valid for 30 days, requires an eSIM-ready phone)

Using Your Mobile Phone In The USA

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

• You can roam on a UK-based SIM card. This is the easiest and 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 your usage.
• You can buy a US-based SIM card on arrival. If you’re a frequent traveller to the USA or if you need a US-based phone number (+1), you can get a local SIM from one of the US networks. However, this is typically a more expensive option unless you regularly travel for an extended amount of time.
• You can buy a data-only eSIM for the USA. You can get a data-only USA eSIM from Airalo. This will give you a low-cost allowance of mobile data. However, you’ll need to use your normal SIM card for calling and texting (for which your standard roaming rates will apply).

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

Roaming on your UK SIM card	Buying a US SIM card on arrival	Buying a data eSIM for the US
Best for one-off or occasional trips to the US.	Best for frequent travellers to the US.	Best if you’re departing soon and want an eSIM quickly.
You’ll have a UK-based number (beginning with +44).	You’ll have a US-based number (beginning with +1).	Data-only service. Use your normal SIM for calls (roaming fees apply).
We recommend Three’s Pay As You Go SIM. Plans start from £10/month with inclusive USA roaming.	Choose a SIM from AT&T or T-Mobile USA. Prices start from $30/month (£26), plus tax and activation fees.	Get an eSIM from Airalo. Prices start from $11/month (~£8.10) for a data-only service.
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).	You can set up and activate your plan on any compatible eSIM-ready phone.
You can continue using 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.	Your eSIM plan will expire at the end of the validity period.

For most people, we’d normally recommend roaming on a UK-based SIM card. This is likely to give you the best overall value, especially when you account for the cost of calling and texting. For instance, Three UK offers Pay As You Go plans from £10. These plans last for one calendar month and come with roaming in the USA at no extra cost (up to 12GB data, 3000 minutes and 3000 texts). There’s no contract and no credit check required when you sign up.

If you have an eSIM-ready phone (including the iPhone 11, Galaxy S20, Pixel 3 and newer devices), a data-only eSIM from Airalo is also worth considering. This can be a good option if you only need a small amount of data. However, you’ll need to take into account the cost of calls and texts on your regular SIM card. This is because the eSIM will only cover your data usage in the USA.

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: 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 add-on costing £25 per month.
• O2: 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 Virgin Media as a Volt customer. For everyone else, there’s a fee of £6 per day to use your phone in the USA.
• Three: If you have a Three Pay As You Go SIM card, you’ll be able to roam at no extra cost when you’re travelling in the USA. Meanwhile, if you’re a Three Pay Monthly customer, there’ll be a £5 daily charge (unless you have a Value or Complete plan, in which case you’ll get a certain number of daily passes to use during your contract).
• Vodafone: 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 you travel in the USA. Otherwise, it will cost you an extra £7.39 per day.

Best USA Roaming Deals

If your current mobile plan does not give you inclusive roaming in the USA, we’d recommend getting a Three Pay As You Go SIM card for the duration of your trip. This will give you inclusive roaming in the USA (up to 12GB of data per month).

Network	Data	Monthly Cost
Unlimited mins Unlimited texts	12GB data	£10.00 per month No contract	See deal
Unlimited mins Unlimited texts	40GB data Up to 12GB in the USA	£13.50 per month No contract	See deal
Unlimited mins Unlimited texts	80GB data Up to 12GB in the USA	£18.00 per month No contract	See deal
Unlimited mins Unlimited texts	Unlimited data Up to 12GB in the USA	£31.50 per month No contract	See deal

You’ll also be able to use your inclusive minutes for calling home to the UK, and for calling other UK-based phone numbers (such as friends and family who are also travelling abroad with you). There’s a fair usage limit of 3,000 minutes and 3,000 texts per month in the USA.

The main disadvantage of Three is the fact that you aren’t able to use the inclusive minutes for calling US-based phone numbers (those beginning with +1). Instead, 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 a call.

There’s no contract and no credit check on Three’s Pay As You Go service. Although you’re able to continue using the SIM card when you get back to the UK, there’s no commitment and you’re able to pause or cancel your plan at any time.

Get 12GB data & 3,000 minutes in the USA for £10 →

Standard Roaming Rates

If your current provider does not 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
EE	£1.66/minute	£1.66/minute	82p/text	£6.74/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	49p/minute	49p/minute	49p/text	9p/MB
Lyca Mobile	£2.10/minute	96p/minute	48p/text	£2/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	No extra cost on Pay As You Go £5/day on Pay Monthly to use your UK allowances of minutes, texts & data
Vodafone	£7.39/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.

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. With 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, it’s possible to get a prepaid plan from $30 per month (approximately £23.90) plus tax. This will get you 5GB of data and unlimited US minutes. There are also unlimited international texts included (to the US, the UK and more than 200 other countries).

If you’re looking for more data, there’s 15GB data for $40 per month (approx £31.90) plus tax, and unlimited data from $50 per month (approx £39.80) plus tax.

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

Network	Minutes	Texts	Data	Monthly Cost
	Unlimited to US	Unlimited intl.	5GB	US$30.00 (~£23.90) plus tax
	Unlimited to US	Unlimited intl.	8GB	US$33.00 (~£26.30) plus tax
	Unlimited to US	Unlimited intl.	15GB	US$40.00 (~£31.90) plus tax
	Unlimited to US	Unlimited intl.	Unlimited† (speed limits)	US$50.00 (~£39.80) plus tax
	Unlimited to US	Unlimited intl.	Unlimited	US$65.00 (~£51.80) plus tax

† On AT&T’s $50/month Unlimited plan, you’ll get speeds of up to 3Mbps on the first 30GB data per month. After that, speeds are slowed down to a maximum of 1.5Mbps. The use of tethering and personal hotspot is not included on this plan. The $65/month plan comes with faster speeds and 5GB of personal hotspot data.

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 (however, this can vary depending on where you get your SIM).

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. This 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 in the UK (now a 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
	Unlimited to US	Unlimited to US	10GB	US$40.00 (~£31.90) plus tax
	Unlimited to US	Unlimited to US	Unlimited†	US$50.00 (~£39.80) plus tax
	Unlimited to US	Unlimited to US	Unlimited††	US$60.00 (~£47.80) 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) 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.

eSIMs For The United States

If you have a fairly modern smartphones with support for eSIM technology, you can order a data-only eSIM from Airalo. Offered under the Change Mobile brand, Airalo’s US eSIM can be used in an iPhone 11, Galaxy S20, Pixel 3 and newer devices.

The main benefit of getting an eSIM plan is the fact it’s available straight away as an over-the-air download. There’s no need to wait for a SIM card to arrive in the post or to get a SIM card from the shop when you arrive. It’s also a lower-cost option if you don’t need the ability to call or text when you’re in the USA.

As the Change Mobile eSIM is technically based outside the USA, you’re able to avoid local US taxes and fees, which would otherwise apply if you were getting a SIM card from AT&T or T-Mobile USA.

The main disadvantage of an eSIM plan is the fact you’re getting a data-only service. If you need to make or receive phone calls and text messages whilst you’re in the USA, you’ll need to use your regular SIM card for that instead. You’ll then incur additional international roaming fees (this can easily add up to £5 for a three-minute call). For that reason, we’d only recommend getting an eSIM if you don’t envision yourself needing to make or receive phone calls in the USA.

The following table shows the eSIM plans that are available from Airalo (Change Mobile):

Network	Data	Plan Cost
Data-only eSIM No calls included	1GB data	US$4.50 (approx £3.30) 7 days validity	See deal
Data-only eSIM No calls included	2GB data	US$8.00 (approx £5.90) 15 days validity	See deal
Data-only eSIM No calls included	3GB data	US$11.00 (approx £8.10) 30 days validity	See deal
Data-only eSIM No calls included	5GB data	US$16.00 (approx £11.80) 30 days validity	See deal
Data-only eSIM No calls included	10GB data	US$26.00 (approx £19.20) 30 days validity	See deal
Data-only eSIM No calls included	20GB data	US$42.00 (approx £31.00) 30 days validity	See deal

As a special offer for July 2025, you can get a 10% discount on your Change Mobile eSIM. If you’re new to Airalo, you’ll be able to enter the KEN10 voucher code at checkout to get 10% off. Alternatively, if you’re an existing Airalo customer, there’s a 5% discount available with the KEN5 voucher code.

See all USA eSIM deals →

If you’re using an eSIM from Airalo, you’ll get access to the T-Mobile and Verizon US mobile networks. Your eSIM plan will not work outside the USA (e.g. in Canada, Mexico or the Caribbean).

Handset & Network Compatibility

It’s now strongly recommended that you use a mobile phone that’s compatible with 4G Calling (VoLTE) technology in the USA. In most areas of the US, VoLTE technology is now a prerequisite if you want to make or receive phone calls.

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 unless your phone has 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. Although you can technically use it on Verizon, 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. 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 US$21 per person (approximately £17) 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.
2. 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).
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 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.