There’s nothing quite like travelling in the United States. It’s a massive, incredibly diverse country. The non-stop action of New York City. The wide-open plains of Montana. Bubbling springs at Yellowstone, muscle-bound beaches in Miami, and much, much more.

For a country that leads the world in technology, though, the prepaid SIM card market for international visitors has long been surprisingly confusing, limited and expensive. With incompatible technologies between providers, locked phones, and post-paid plans the norm for locals, tourists have been poorly catered for.

Things have got slightly better in the last few years, although still a far cry from regions like South East Asia or even Western Europe. Still, you can now at least easily find a store, buy a SIM card that will work in your phone, pay a not-totally-unreasonable amount of money for a useful amount of calls, text and data, and get it all done in a few minutes. That’s a vast improvement.


  • We recommend T-Mobile for most travellers
  • Also consider AT&T if you're spending time in more remote areas

There are four main cell service providers in the United States — but only two of them are of much interest to travellers.

Verizon (which has one of the largest networks) and Sprint use CDMA technology that’s incompatible with almost any phone not sold by them. Unless you’re planning to buy a phone specifically for your time in the US, you’re out of luck with those two.

Of the other two companies, AT&T has the largest (and often, most congested) network, offering coverage throughout most of the continental United States (map). It’s a big country, though. If you’re planning on road-tripping through lightly-populated states like Nebraska, Montana and a few others, you’ll still hit some very large dead spots.

T-Mobile has less coverage in rural areas (map), with particularly large gaps in Idaho, Nevada, Oregon, Montana, New Mexico and eastern California. On the upside, when you do have signal, data speeds will often be reasonably fast.

There are several resellers of service on both networks — and none are particularly great. Prices are typically only slightly less than buying direct from the provider, often with data speed limits, poor customer service and purchasing difficulties for overseas visitors without a local address or credit card.

With my six week trip to the US largely confined to the cities, coverage areas weren’t going to be a problem with either provider. I intended to buy from AT&T, but after encountering an unhelpful salesperson in a Seattle store, decided to go for T-Mobile instead. Pricing and data allowances were slightly better, and in-store service was fast and efficient.

Note that very few international phones will get LTE service with either company, as the US uses different frequencies to most countries outside North America. To complicate things further, both AT&T and T-Mobile use “4G’ to describe what the rest of the world knows as “HSPA+” or 3.5G. As a result, you’ll likely see 4G on your phone screen, but it’s not LTE!


Offering prepaid SIM cards at international airports doesn’t seem to have caught on in the US. I’ve flown into several in the country, and don’t recall seeing marked kiosks or signage at any of them. Fortunately, T-Mobile stores are quite common in large cities, and even smaller places should have at least one store.

I walked into a retail store in Seattle’s Capitol Hill, asked about prices, and walked out with an activated SIM card in under ten minutes. It had cut-outs for both micro and nano sizes. The process was simple — confirm you’ve got an unlocked phone, specify the plan you’d like, and hand over the money. You’ll get a receipt with your phone number printed on it.

It might be worth putting the SIM in your phone and confirming it works straight away. I didn’t have any problems, but am always a little nervous when I don’t see the card working in my phone before leaving the store.


While you shouldn’t expect any real bargains on prepaid cell service in the US, prices have dropped a little from last time I was in the country.

Note: for extra bonus confusion, you often can’t get the same deals in-store that you can online, with either company. Since most international visitors will be buying their SIM from a store, I’ve focused on those options — but if you have a US shipping address you can use, it’s worth checking out the online-only plans as well.

Unlimited calls and texts are common on most plans. AT&T’s prepaid monthly smartphone plans started at $45, with 2Gb of data. T-Mobile charged $40 for 3GB of data, $50/5GB or $60/10Gb. I went with the cheapest option.

At both the AT&T and T-Mobile stores I visited, the SIM card itself was free. This isn’t always the case, however, so definitely check before committing.

Don’t forget, you’ll pay sales tax on top of the quoted price, ranging from nothing to nearly 10% depending on which state you’re in at the time.

Note: T-Mobile doesn’t offer any prepaid data-only plan instore. AT&T does — but only for tablets. If you happen to mention you’ll be using it in a phone, they won’t sell it to you! I’ve read reports of problems activating an AT&T data-only SIM in a phone as well, so don’t necessarily expect it to work if that’s what you want to do.


Can't be bothered with the hassle of buying a local SIM in the United States? KnowRoaming topped our international SIM card comparison.

The company's SIM cards, stickers and hotspots can be sent out ahead of time, so you'll hit the ground running in 200 countries, and save up to 85% on roaming fees while you're there. Unlike other companies, using WhatsApp for texts and calls anywhere in the world is absolutely free.

Find out more here.



You can top-up your T-Mobile account online, using just your phone number and a credit or debit card. Since international cards work with this method, it’s probably the easiest way to do it.

Failing that, any T-Mobile store will be able to help you out, as well as authorised retailers. You can check locations here.


As mentioned above, T-Mobile coverage is good in most large towns and cities, but drops away in rural areas, with large dead zones in several states. Compare the service map to your intended destinations, and if you’re going to be spending significant time driving or staying in places without signal, consider AT&T instead.

“4G” speeds in central Seattle were good, with strong signal both inside and outdoors. Voice calls were clear, and SMS delivery was reliable.

T-Mobile 4G speeds
Check out our guides to buying SIM cards in many other countries here.
Want more? Grab our free 5000 word guide
Plus regular tips, discounts and the best travel tech advice.
No spam, ever.

30 Responses

  1. Rick

    You should really check out Cricket in the US. It’s on the ATT network (and is owned by ATT I believe) so same coverage. It’s $40 for 2.5 GB a month (if you sign up for autopay they knock off $5) and all taxes/fees are included. Additional GB are $10 for 1GB.
    Service was friendly and getting a SIM swapped and activated took 10 minutes.

    • Dave Dean

      I considered them, but in the end opted not to use Cricket because they throttle data speeds quite heavily. For most international visitors who won’t have a phone that supports US LTE frequencies and will only get 3G, the max speed will be 4Mbps. That’s not terrible, but since there’s little price difference between Cricket, T-Mobile and even AT&T, I decided to go for T-Mobile’s unthrottled option with a bit more data.

      If I needed to be on the AT&T network for coverage reasons and didn’t care so much about download speed, though, I’d likely choose Cricket.

    • Dave Dean

      Most will work, but it’s more to do with how much you want to pay — you’ll typically be paying roaming fees in whichever country you didn’t buy the SIM in. Most carriers have some sort of roaming package available for the other country, but they’re typically not great value if you want to use your phone much at all.

  2. TSP

    When I come to a store and buy a SIM card, will I also be able to register for a 3G/4G data packet or will it already be part of the prepaid plan? Many thanks,

    • Dave Dean

      It will probably be part of the prepaid plan already. You may be able to get a talk/text-only plan if you really want one, but most plans include a data allowance.

  3. Kate Palmano

    Hi Dave,

    Are you able to recommend the best prepaid SIM providers in Canada? I’ll need txt and talk but mainly data for maps. Many thanks.

  4. MAXIE Smith

    Apart from the sim for my iPhone, will I be able to obtain wifi access for my iPad?

    We are doing a road trip around Co, Wy, Ut and SD so will be in some quite isolated spots, therefore I need access to my gadgets!

    • Dave Dean

      I can’t answer that with certainty, as it depends a little where you’re going, but given that most hotels, hostels, chain restaurants and many other places in the US offer free Wi-fi of some description, you should be fine. I did a road trip from Denver to Seattle through some pretty isolated spots a few years ago, and was able to find Wi-fi anywhere I needed it.

  5. MHA

    Regarding data speeds for iPhone 6, is AT&T preferred over TMobile? I read older posts from ~2013 that mentioned iPhone incompatibility with TMobile.
    Also, which provider is best if you need calls to/from international cellphones?

    • Dave Dean

      It really depends where you are. AT&T has coverage over a wider area, but in big cities, the network is often more congested than T-Mobile, which means lower data speeds.

      There’s no incompatibility between recent iPhones and the T-Mobile network — I imagine what you were seeing was problems with older international models and the frequencies used by T-Mobile’s higher-speed network. Both the phones and the network have changed since then.

      Regarding international calling, you’ll need to check each company’s rates for the countries you plan to call — there’s no one-size-fits-all answer to your question.

  6. Jess

    Dave thank you so much!! Your article was a God sent as I have a teenage boy and he is going away to the USA to school and I tried looking over a bunch of phone options and that was becoming a very wearisome so I decided to check for just switching the sim card to the country you are in (old school) and found your article.

    I am so relieved I can just look now into the other aspects of his time as as student.

  7. Eyal

    Did you see a price hike for Data sim cards lately? The prices I see now for 10GB in T-Mobile and at&t for pre-paid SIM cards are around 80-85 USD.

    • Dave Dean

      I didn’t, but to be honest, I haven’t been monitoring them. After T-Mobile said they didn’t sell data SIMs instore, and AT&T refused to sell me one for use in a smartphone, I just gave up on the idea for most US-bound travellers.

      Those prices don’t seem very surprising, though — 10GB is considered quite a lot of data for a prepaid monthly cell plan in the US, so I’d expect the prices to be relatively high.

  8. Onur

    Headed to US for a two week road-trip and plan to be in some remote areas as well as cities. This will help a lot in reducing my time to get started once I land.

    I have used your advice for local SIMS in South East Asia previously and it was dead accurate, so thank you for both series!

  9. Thanit

    Thank you for the wonderful site. I am arriving Seattle International Airport next week. Is there any store at the Airport I can buy the prepaid Sim from either AT&T or T-Mobile?
    Would be great to have a local number and internet to use when landed.

    • Dave Dean

      I didn’t see any AT&T or T-Mobile branding on arrival at Seatac earlier this year. This thread suggests it might be possible from Hudsons or Kens Baggage, but I don’t have any first-hand experience of that, or even where in the airport those stores are.

  10. Jimmy

    Hi, I will be arriving San Francisco in 2 weeks time, will be spending couple of days in SF and LA, thereafter move to NYC for 2 weeks. Could you advise whether there are any kiosk in SF airport to purchase SIM for both calls, text and data. Also which is the best operator for SIM ? As I will be using mainly datas with few calls, please advise the best package to purchase.


    • Dave Dean

      I don’t know whether there is anywhere to buy a SIM at San Francisco airport. In terms of what to buy, please use the information in the article to make your decision about that.

  11. Mariana

    Hello, i will be in New York for 1 week in december for the christmas. Can you recommend me a simcard for just one week. I have a samsung S4 mini and it’s unlocked. What do i need to pay attention to. I will be making calls in USA and maybe on the street send an app. The rest i will do in my hotel room. What do you recmmend?

    Thank you.

    • Dave Dean

      Just go for whatever the lowest cost call/text/data package option is at the time, with either AT&T or T-Mobile. There’s unlikely to be much difference between the cost or quality of service you get with either carrier in New York.

  12. Jackie Spang

    Hi! I live in Buffalo, NY and I have a French exchange student with a 3 year old Nokia phone that died last night. He only uses it when connected to wi fi (and to listen to music.) I know absolutely nothing about cell phones! I believe it has a micro sim.What should we do?
    Thank you for any advice!

  13. Ryan

    Hello, I would like to let you know that most supermarkets, chains stores electronic and pharmacies and even convienence stores sell prepaid sim card kits and refill cards now. Prices vary by location. One does not have to go to the Carrier store to get one. The sim card kit will come with instructions on how to activate it as well (very easy).Just to let you know that AT&T’s prepaid service is called Gophone. The current pricing plan is as follows

    $30 unlimited monthly voice/SMS, no data
    $45 plan ULTD Voice,SMS, intl SMS and 3GB of data (30Days)

    $60 plan ULTD voice,SMS,intl sms in the US,Canada,& Mexico with 6 GB of data. add more for $10 a gigabyte. (30days)Also, if you are on the monthly plan and you do not refill after 30 days, then you have 60 days to refill your account. If not, the account will be terminated and your phone number be lost.

    Hope this is helpful to anyone.

    • Clive

      Thanks Ryan, I’m from UK and was casually keeping an eye out for mobile phone and some card kiosks (like the ones in UK) in Berkeley today and your posts explain why I saw none. The 30 dollar option will be fine for my calling needs.

  14. Chris Cribbs

    Hi Ryan,
    The article and links are very good. Can you update me on any changes or suggestions for a three week visit to the US – prepaid sim?
    We used ZipSim last year – and like many products has its strengths and weakness. Would you suggest KnowRoaming over ZipSim or is there a better sim on the market now? Needing Data & Voice packages (data for google maps when driving).


Leave a Reply

Your email address will not be published. Required fields are marked *