In the early days of smartphones, most devices were purchased through the carrier of your choice, locked to a specific carrier without the option to leave your carrier behind to find a better deal somewhere else. Most Android phones available prior to the Samsung Galaxy S III even had carrier customization in both the software and the hardware, with special carrier-exclusive variants of the Galaxy S II available on carriers like AT&T (with the “Samsung Galaxy S II Skyrocket”) and Sprint (the ludicrously-named “Samsung Galaxy S II Epic 4G Touch, later renamed to simply “Galaxy S II 4G”). Even Apple’s iPhone was a carrier exclusive throughout the first three devices, only available to AT&T customers before Apple finally released a Verizon-based iPhone 4 in February of 2011, and a Sprint-capable model of both the iPhone 4 and 4S was announced during the latter’s unveiling later that same year.
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Since then, we’ve seen unlocked devices become the new norm. While lower-budget phones typically only work on GSM carriers (that is, T-Mobile and AT&T), most flagship devices have support for all four carriers. This is something companies like Motorola, Apple, and HTC have gotten really good at, allowing users to buy one device and pick the right carrier for them. These manufacturers sell unlocked devices through their own storefront, or through third-party sellers like Amazon and eBay, allowing manufacturers to easily gain access to devices that work on any and every cellular provider in the United States (and typically, many European countries as well). Even some cell service-branded devices ship unlocked, able to be used on other carriers outside of the original provider, though that isn’t as common of a practice as some users might wish for (and typically includes some reservations).
Since not all phones ship unlocked from your manufacturers or carriers, it’s important to know whether or not your existing device works outside of your current carrier. You’ll want to look for a few distinct factors when looking to see if your device is unlocked, all of which we’ll cover below. Let’s take a look at this guide to unlocked smartphones.
What does an unlocked smartphone allow you to do?
Simply put, the biggest difference between an unlocked and locked smartphone is the ability to use your device on other carriers once you’ve inserted a compatible SIM card into your device. This is really the only difference between a locked and unlocked device; you can still install the same applications from the App Store on iOS or the Play Store on Android, and still perform the same actions as any smartphone, like sending text messages, placing phone calls, and browsing the web.
Now, that said, there are a few other differences between an unlocked and locked device. While Apple handles updates for all its phones directly, Android updates are typically pushed out by the carrier after the manufacturer has finished building the software for the device. This means that, on occasion, OS updates for Android devices can get caught up in “carrier testing,” while unlocked devices and devices on other carriers have already finished the update. This has occurred with dozens of smartphones, most recently (as of writing) the HTC One M9, a phone released in 2015. Throughout the spring of 2017, the device was updated to Android 7.0 Nougat on T-Mobile, Sprint, and AT&T, in that order. This left the Verizon model on Android 6.0 for a full six months after the T-Mobile version, until the Verizon variant was finally updated in late September. But the unlocked version of the M9? That phone received its Android 7.0 update in December of 2016—months before the carrier versions of the device would start rolling out their own versions of the same software.
This is primarily a problem with Android. Apple’s own share of the market is so powerful that they can essentially bypass the restrictions of carriers like Verizon and AT&T. Android manufacturers largely don’t have that kind of clout with carriers; they need to sell their devices in stores to make money on their devices, and are willing to load their phone with carrier-branded apps and sponsored bloatware that many Android fans are used to uninstalling or disabling on their device out of the box. The only Android OEM with the same kind of power as Apple is Samsung, but they too tend to fall behind carrier lines. In a positive development, Samsung does seem to be working towards a more Apple-like agreement with carriers—the S8 and S8+, along with the Note8, all shipped this year without any carrier branding—but they still allow manufacturers like AT&T and Verizon to install DirecTV and Go90, respectively.
We should also mention that unlocked devices don’t always have improved support over the carrier models. The unlocked version of the Galaxy S7 and S7 edge were, infamously, left behind on Android 6.0 Marshmallow for months longer than the carrier models, finally receiving the update in May of this year. For comparison, carrier models began to receive the update in January, and even the Verizon model (notoriously the slowest of the four service providers nationwide) was updated to Nougat in March.
So, overall, if you’re an iOS user, the only difference between an unlocked and locked iPhone is the ability to use your device on alternate carriers easily. On Android, the difference is far greater. Software updates will arrive at different times, and your device will include apps and other preinstalled software you won’t be interested in will be found on your device. You might have carrier branding on the back (or, in some cases, front) of your device, though some OEMs are finally starting to move away from that. And of course, you’ll be able to easily use your device on your carrier of choice, while still being able to take advantage of WiFi calling and HD Voice on most carriers.
Do unlocked smartphones work on all four national carriers?
This is actually a really important question. It’s pretty easy to buy an unlocked smartphone from Amazon—they have an entire section of their store dedicated to them—but not every unlocked device is designed to work on multiple carriers. Cellular technology is a bit complicated, and while the move to a single standard for 4G has simplified things a bit, using a device between all four carriers in the United States is still a bit tricky. The legacy of a fragmented 3G market lives on, and though LTE is available in most parts of the nation at this point, having 3G as a fallback is still important for most consumers, and certain unlocked devices don’t have support for older bands.
Let’s back up a bit. If you’re unfamiliar with cellular technology in the United states, it can be a bit complicated to understand. In the early 2000s, most cellular technology was built off of two different standards: GSM (which came around in the 1980s and was adopted by most of the world, including Europe), and CDMA (built by Qualcomm, now known for powering most Android devices on the market). Both AT&T (previously Cingular) and T-Mobile built their networks off of GSM technology, which meant unlocked phones were easy to bring to both carriers without much work. This continued throughout the 2G and 3G data days, and when it came time to build 4G-based networks, both carriers eventually evolved to LTE, a continuation of the GSM standards. Verizon and Sprint, meanwhile, chose to use CDMA technology for their devices, with their 1X networks being about equal to the 2G networks offered by AT&T and T-Mobile, and their EV-DO networks being equivalent GSM-based 3G networks. However, CDMA was far more proprietary than GSM, and it meant that the cellular information for the device was built into the phone, instead of using a SIM card as GSM-based carriers did. This meant you had to call an activation number when you received a new phone. It also made changing devices more difficult, and made using unlocked devices impossible.
This all changed with the move to LTE. Sprint had originally bet on WiMAX technology over LTE, but the speed and connectivity benefits that LTE offered over WiMAX simply won out in the end. This meant that, as of about 2013, all four carriers in the United States were finally on a SIM-based standard, theoretically allowing for more competition and more interoperability. But—and this shouldn’t surprise you, if you know a lot about US-based carriers—that’s not exactly what ended up happening. Instead, most carriers have taken to using separate frequency bands, and limiting the bands used in their exclusive, locked-down devices. While phones that worked on AT&T typically also supported some T-Mobile bands, Verizon and Sprint both supported different bands that kept phones from working together out of the box.
In 2014, this slowly started to change. Motorola was the first major OEM to offer unlocked versions of their smartphones that worked on all providers, with both later entries in their X and G series of devices supporting nearly every major and minor carrier in the United States. This has continued to be a trend with them: their unlocked Moto G4 and Moto G5, along with the Moto Z2 Play and Moto E4 work on most or all carriers out of the box, though with some limitations on AT&T (typically around features like HD Voice or WiFi calling). They aren’t perfect though, as the Moto Z2 Force, their flagship device for 2017, has carrier-specific models for all four national providers. Samsung’s Galaxy S8 and S8+ are both available as unlocked devices that work on all four carriers, as is the HTC U11—though in the case of the latter, the lack of a CDMA radio means that the device won’t function on 3G when using a Verizon or Sprint SIM card. This is a major problem with certain unlocked devices, so it’s always important to check carrier details in the description of your device before buying. And as far as the iPhone is considered, all modern iPhones, including the iPhone 7, iPhone 8 and the upcoming iPhone X, use Qualcomm radios that support both CDMA and GSM carriers, which means they work with all four carriers when purchased directly from Apple.
Ultimately, there is no simple answer to whether unlocked smartphones work on all four national carriers. Certain phones, especially modern devices released in 2016 or 2017, are typically built to be used on most devices, since it’s easier for OEMs to build one unlocked model for all four carriers. That said, it really depends on your device, and if you’re considering purchasing an unlocked device, either new or used/refurbished through a site like eBay, you’ll want to do some research to determine whether or not your device can be used on your current carrier.
How do I know if my phone is unlocked?
Based on everything this guide has covered so far, you can pretty much guarantee that this isn’t an easy question to answer. Simply put, if you bought your phone through a carrier, either on a two-year contract or a monthly payment plan, your phone isn’t technically unlocked, even if it does support other carriers. Since you’ve made an agreement with that carrier, either through the signing of a contract or (more common these days) through a payment plan, you’ll have to stick around with that carrier until the contract is up or the plan has been paid off. You can do the latter at any time though, and once your device is paid for, if your phone is SIM unlocked, you can use it on any carrier of your choice.
Of course, that’s the major question: how can you tell if your device is SIM unlocked once it’s been paid off ? Well, the answer really depends on what phone you’re using and whether or not it’s designed to be used on multiple carriers. Let’s take a deeper look.
If you’re an iOS user, the answer is pretty simple. Either you bought your device straight from Apple (either for full price or through their iPhone Upgrade Program), through a third-party like Best Buy, or through your carrier. If you purchased your device from Apple, you had the choice to either buy a model from a preselected carrier or to purchase an iPhone without a SIM card. If you chose the latter, your device is already unlocked, and you can use any SIM card with your device and pick up a full signal on any carrier. That said, preselected carrier models from Apple, along with models bought from both Best Buy and carriers all include a SIM card pre-inserted into your device. These iPhones are, for the moment, technically locked to your carrier—but that said, they can almost always be unlocked with little effort on your part, something we’ll discuss in the next section of this guide.
If you don’t remember whether you purchased an unlocked or carrier-specific iPhone, iOS makes it easy to check whether your device is still locked. Dive into the Settings menu on your phone, select “Mobile Data,” then select “Mobile Data Options.” Here, your device will either display an option for “Mobile Data Network,” which would allow you to select the carrier of your choice, or it won’t, in which case, your iPhone is currently locked. Alternatively, you can simply power down your phone, place the new SIM card for your new carrier into the SIM tray on the side of the iPhone, then power the device back on. Try to place a phone call or use mobile data to see if your device supports your carrier. If it does, you’re all set to use the device on another network. If it doesn’t, don’t worry—all iPhones can be unlocked by the carrier.
As with iOS, the easiest way to check if your Android device is unlocked is to simply throw a SIM card from an alternate carrier into your device to test whether the phone works or not. Typically, if you bought your phone through a carrier (as most Android users do) or through a reseller and the listing did not specifically say the phone was unlocked (for an example of this, see the Moto G5 Plus listing on Amazon here), your phone is probably locked. We’ll discuss how carriers lock and unlock phones below, but basically, if you’re on a contract or on a payment plan, your device is probably locked to your carrier for the time being.
If you don’t happen to have an alternate SIM card from a different carrier to test out on your device, there is a way to test the IMEI number on your device to determine its locked or unlocked status. IMEI.info has been around since 2012, allowing users to test their IMEI numbers to reveal the status on several pieces of information on their devices. It’s not always correct about certain pieces of info, but typically it can provide you with a general idea of whether or not your device is locked. Alternatively, if you don’t feel secure in inputting your IMEI number into a website, you can contact your carrier’s support for more information.
Can I unlock my smartphone if it’s locked to a carrier?
Once again, the answer is a bit more complex than a simple yes or no. If your device has the capabilities to pick up various networks beyond the one it was designed for and sold through, then yes, once your phone is paid off, you’re free to stick any SIM card you’d like into your device. For example, the Verizon-based Galaxy S7 edge was sold SIM unlocked, despite having Verizon branding and Verizon apps included on the device. So long as you paid the device off in full, you were free to use it on any compatible carrier. To continue using the Verizon-branded S7 edge in this example, the built-in bands allowed the phone to function on T-Mobile and AT&T in addition to Verizon, though neither of those carriers offered full compatibility with the phone itself. This means that, though you’ll pick up a signal, both its quality and speed aren’t guaranteed, since the device is missing specific bands that will give you additional function.
Here’s the good news: regardless of your operating system, all four carriers have adopted stances on unlocked devices through their network, and if we’re being honest, the answers might surprise you. Here’s what all four national carriers have had to say on whether the devices purchased through their carrier stores (or through resellers like Best Buy) support other carriers.
- Verizon: Surprisingly, Verizon has been pretty solid about their options for keeping smartphones unlocked on the carrier. All devices sold through both postpay and prepay on Verizon are shipped unlocked, and in fact, Verizon will even allow you to switch the SIM card in the device out for another carrier’s while under contract (of course, you’ll still have to pay your monthly Verizon bill). There’s no number to call or unlocking code to enter—almost every device sold through the carrier can be used without any effort on your part. Verizon had a history of being one of the more locked-down carriers of the 2000s prior to the launch of their LTE network, so their total 180 on unlocking devices is refreshing and welcomed.
- AT&T: You can use pretty much any device sold through AT&T on any other network of your choice, assuming the device is supported by the network you wish to use, though you’ll have to jump through a couple hoops to get there. The good news is that it’s not too difficult to accomplish, so long as you manage to meet the requirements assumed by the company. This includes your device’s IMEI number not being reported stolen or missing, your account must be in “good standing,” without missed payments or large balances owed, and your device must’ve been active on AT&T for sixty days. Assuming you meet the company’s requirements, which can be determined through their online portal, you can unlock your device for any other supported carrier. The bad news: AT&T only allows five devices to be unlocked per year from your account. You might also need to wait a few days before your request is finally processed. It’s a bit of a headache, but at the very least, you can use your device on other carriers once the process is complete.
- T-Mobile: The “Uncarrier” stance on unlocking is eerily similar to what we’ve seen from AT&T. Your device must first be a T-Mobile product, must not be reported as stolen or missing, must be connected to an account in good standing, and be active for forty days on T-Mobile. When it comes to unlock quotas, however, T-Mobile is far more strict than their blue cousin: only two devices can be unlocked every year, making it difficult for a family of three or more to leave the carrier at once. Furthermore, you have to ensure your T-Mobile payments on the device are completely paid. This is in stark contrast to T-Mobile’s most bitter rival, Verizon, where you can use an unlocked device on any carrier at any time, regardless of remaining payments on the device. Assuming you meet those demands, you can contact T-Mobile’s own support to ask for an unlock code for your device. It’s a bit archaic, especially for a carrier that markets itself as the carrier that breaks the rules, but it’s the current system.
- Sprint: Sprint’s own guidelines for unlocking a device are pretty identical to T-Mobile and AT&T. You’ll have to use the device on Sprint’s network for fifty days, ensure your contract has ended or that your lease payment on your device is paid off, hold an account in good standing, and of course, the device can’t be reported as stolen or missing. Sprint’s own documentation on this topic states that phones bought after February 2015 will automatically be unlocked once the device meets these standards, which means you may not have to contact Sprint at all following your device’s lease being paid off. That said, if you do believe you’ve met all standards mentioned in their guidelines and your phone hasn’t been unlocked, you’ll have to contact their customer service for more information.
To reiterate, you’ll still have to make sure your device will work on the carrier of your choice before moving to another carrier. That said, it’s typically pretty easy to find those results on Google. Simply search for your device name with the carrier you started on and the carrier you’re moving to, and a forum post will undoubtedly appear answering your question. That’s for Android users only—iPhone users can move to the carrier of their choice once they’ve unlocked their devices.
One last warning about unlocked Android devices: as we mentioned above, while Apple pushes out their own software updates, most Android users will be subject to your carrier pushing out your update, assuming you didn’t buy your phone unlocked directly from the manufacturer. This means, while your device is fully functional on another carrier, you may not receive updates on your phone while using a different SIM card. Something to keep in mind before you make the switch from a carrier-branded device.
Where Can I Buy Unlocked Devices?
Well, obviously, if you’re looking to purchase an unlocked device, you’ll want to steer clear of carrier stores. This may sound obnoxious or frustrating, especially if you’ve always purchased your devices from carriers through contracts or, more recently, on payment plans, but with the exception of Verizon, any device you buy through a mobile provider will be locked until you pay the full retail price of the device or until your phone contract ends. So instead, you have three choices on where to pick up your phone, and all three have their respective benefits and drawbacks.
Both Amazon and Best Buy have a wide variety of unlocked devices for sale on their marketplaces, with each dedicating a webpage to unlocked devices. Amazon has a wide variety of phones available on their website that are completely unlocked, from budget devices to flagship models like the Essential Phone, the Google Pixel, and the Galaxy S8 and S8 Plus. In addition to these devices, Amazon also offers “Prime-exclusives,” a series of phones that are primarily made of budget devices and phones under the $300 mark. There’s some great phones for sale under the Amazon Prime banner, including the Moto G5 Plus, which has been our top entry for the best cheap smartphones throughout 2017. That said, you’ll have to be an Amazon Prime member to take advantage of the discounts offered on the phone models. Best Buy also has a wide variety of unlocked devices, including flagship Android models like the ones mentioned above, and occasionally even feature Best Buy-exclusive models like the coral blue Galaxy S8 and S8+. If you’re looking to finance these devices instead of paying for the phones in one lump sum, you’ll have to sign up for their respective store cards, which forces you to pay for the device over 12 months (and, unfortunately, could lower your credit score standing). Oh, and as for iPhones, neither retailer carries a large selection of newer models. You can find iPhone 6 and 6S devices on both marketplaces, along with a few unlocked iPhone 7s on Amazon, but neither company has an unlocked iPhone 8.
If you’re interested in financing and don’t mind missing out on some exclusive models and colors, you can go direct to the manufacturer. Apple will sell you an unlocked, SIM-free iPhone for the same price it sells its carrier models, and with their iPhone Upgrade Program, you can pay similar prices we’ve seen from the carriers while also gaining access to 12 month iPhone upgrades and AppleCare+ included in your price. It’s not a bad deal at all, and while it won’t make your device any cheaper compared to buying the device through a carrier, you at least get the benefit of having a quality extended warranty program. Android manufacturers also sell their devices on their own websites typically, and if you search for the unlocked models of their devices, you’ll find them listed alongside the carrier versions. For example, Samsung has their Galaxy S8 line on their website for purchase, with the option to finance the phone over 24 months. Meanwhile, HTC’s 2017 flagship, the U11, is only sold in Sprint carrier stores, but you can buy an unlocked model that supports Verizon, T-Mobile, and AT&T on their website. That said, not all manufacturers offer financing plans, HTC included.
The final method for purchasing your devices is through a seller-based marketplace like Ebay or Swappa. You can pick up factory and user refurbished devices on those sites, right alongside brand new phones, and Ebay listings will typically tell you whether or not the phone is unlocked. If you’re unsure if a phone listed on either store is the unlocked model, typically researching the model number online will alert you whether the device is linked to a specific mobile network or if the device is truly unlocked. For example, Samsung’s Galaxy S8 has dozens of model numbers referring to specific countries and carriers, but the unlocked model sports a U1 at the end of its model number to differentiate that model from the AT&T or Verizon version. If you’re buying a specific carrier version of a device online, make sure to research the buyer first. If the price seems too good to be true, or the seller is a brand-new account, you could be buying a device that has been marked as stolen or missing, which means it could have difficulty registering on any network, regardless of its locked or unlocked status.
Once My Phone is Unlocked, What Can I Do?
Finally, a question that has a simple answer. Once you’ve unlocked your phone from your carrier, you can move to another cell provider of your choice, so long as your device is capable of receiving a signal from that provider. For example, if you purchase an iPhone from Sprint, only to discover your house cannot isn’t included in Sprint’s coverage, you can finish paying off the device in order to leave the company, so long as your account is in good standing (see above). After Sprint unlocks your device, you can purchase a T-Mobile or Verizon SIM card, slot it into your device, and you’re off to the races.
That said, SIM cards don’t provide any other information beyond the cellular connection for your device (though in some cases, you can save some small amounts of data to your phone’s SIM card, like a mircoSD card). For example, one of the comments on an older version of this article asked what would happen if you placed your spouse’s SIM card into your device. The answer is easy: that phone will adapt to your spouse’s phone line, including the number that people use to contact them. That’s it—everything else, including apps, photos, and music, is tied to either the Apple or Google account tied to the phone inside your settings, or stored on the internal storage of your phone. If you’re trying to set up an old device for a spouse, you’ll want to wipe that device first and set it up as a new phone; that said, beyond a phone number, you won’t gain any other data from the SIM card.
In 2017, the difference between buying a locked carrier model of a device and an unlocked version has never been clearer. With most carriers no longer offering two-year subsidies on devices, consumers are finally beginning to pay full price for their devices, allowing them more freedom to move between mobile providers. And with the prevalence of LTE in the United States, more and more phones finally support all four national providers at once, giving consumers more selection for their devices than ever before. Before you upgrade your device on a payment plan with your carrier, do your research into unlocked models of your favorite devices. In the long run, choosing an unlocked model with a payment plan through the manufacturer might be a better choice for you and your wallet—especially if you’re ever interested in switching carriers.