There’s nothing quite like traveling 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 somewhat better in the last few years, but it’s still a far cry from regions like Southeast Asia or even Western Europe.
There are three main cell service providers in the United States: Verizon, AT&T, and T-Mobile. Note, however, that many older international phone models won’t get LTE service with any carrier, as the providers use different frequencies to most countries outside North America. 5G service with a non-US phone is even less likely right now. If you’re not sure whether your phone is physically capable of getting connected, this site may help.
Verizon (which has one of the largest networks) used to only use CDMA technology incompatible with almost any phone not sold by them, but has been rolling out GSM-based LTE and 5G service in recent years.
This means a small range of phones sold overseas (including recent iPhones) will now connect to its LTE network. Its prepaid service costs more than the competition, however, and many international phones still won’t work.
As a result, it’s hard to recommend Verizon to international visitors unless you know your phone is compatible, and are traveling somewhere that only Verizon offers reliable coverage.
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 Idaho, Montana, and a few others, you’ll still hit some very large dead spots.
AT&T is in the process of shutting down its 3G network. Scheduled to be finished by early 2022, it will leave LTE and 5G as the only remaining options.
Coupled with this, the company has issued a short whitelist of devices that are permitted to be activated on its network. Anything else won’t be allowed, which is likely to cause major problems for international visitors when it comes into force. We’ll be keeping a close eye on this, and change our recommendations if necessary.
T-Mobile has less coverage in rural areas (map), with particularly large gaps in Idaho, Nevada, Oregon, Montana, Utah, and eastern California. On the upside, downloads will often be reasonably fast when you do have service, typically exceeding AT&T’s speeds in major networks.
Like AT&T, T-Mobile is also shutting down its older networks so it can reuse its radio spectrum for 5G. There’s no set deadline for this to be completed yet, but the end result will be the same: LTE and 5G will be the only options available.
That’s true whether you want voice, text, or data, and any phone that doesn’t support Voice-over-LTE (VoLTE) is already prohibited from being activated on the T-Mobile network. That’s not as restrictive as AT&T’s policy, but will almost certainly still cause problems for international visitors (and locals) with older phones.
With most of my trips to the US largely confined to the cities, coverage areas haven’t been a major problem with either provider. Pricing and data allowances have typically been quite similar between AT&T and T-Mobile, and in my experience, the knowledge and service levels of the in-store staff have been much better with T-Mobile.
There are several resellers of service on both networks. Prices are typically only slightly less than buying directly from the provider, often with data speed limits, poor customer service, and in some cases, purchasing difficulties for overseas visitors without a local address or credit card.
That said, it can be worth calling into a Walmart and seeing what’s available, as you may find discounted deals on offer from the cheaper providers. You’ll need to activate the SIM card yourself, and don’t expect much in the way of customer support, but on the upside there’ll likely be fewer ID requirements to go with it.
Note that US providers seem to treat 4G and 5G as marketing terms, often unrelated to actual technical standards. Don’t necessarily believe what’s showing at the top of your phone screen!
How to Buy a SIM Card in the United States
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. There might be the occasional airport convenience store selling a SIM of some sort, but you can’t rely on it.
Fortunately, T-Mobile stores are quite common in large cities, and even smaller places should have at least one. I’ve bought SIMs in stores in Santa Monica in Los Angeles, and Seattle’s Capitol Hill. In both cases, I 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’s always worth putting the SIM in your phone and confirming it works straight away. I didn’t have any problems — mine took less than a minute to activate both times — but I’m always a little nervous when I don’t see the card working in my phone before leaving the store.
If you have a recent iPhone (XS or newer), however, there’s an even easier option. T-Mobile provides a prepaid eSIM alternative to buying a physical SIM card, aimed at those traveling in the country or otherwise wanting a short-term option. This page has all the details, but the basics are simple: download the app, provide basic contact and billing details, then activate the eSIM and a call, text, and data package on your phone.
With virtually every other cell provider in the world running scared of prepaid eSIM options, it’s a real breath of fresh air. At least if you’re using an iPhone.
Prepaid SIM Costs
While you shouldn’t expect any real bargains on prepaid cell service in the US, prices are getting better for light to moderate use.
Note: you can’t always 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’re using T-Mobile’s eSIM option or have a US shipping address you can use, it’s worth checking out the online-only plans as well.
Unlimited (or at least large numbers of) calls and texts are standard on most plans. AT&T’s prepaid monthly smartphone plans start at $30 for 5GB of data, with $40 for 15GB or $65 for unlimited. T-Mobile’s standard prepaid plans start at $15 for 2.5GB of data. If you need more, it’s $25 for 5.5GB, $40 for 10GB, or $50 for unlimited.
At both the AT&T and T-Mobile stores I visited, the SIM card and activation were free. This isn’t always the case, however, so definitely check before committing. You’ll also pay sales tax on top of the quoted price. This ranges from nothing to nearly 10%, depending on which state you’re in at the time.
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 (or at least, mine did,) 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 authorized retailers. You can check locations here.
If you’re using the eSIM app, you can manage and pay for plans that way instead.
Coverage and Data Speeds
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.
Data speeds in Los Angeles, Seattle, Portland, Austin, and elsewhere were all pretty good, with strong signal both inside and outdoors. Voice calls were clear, and SMS delivery was reliable.
Check out our guides to buying SIM cards in many other countries here.