Explained: What is an Unlocked Smartphone?

Many of you may have heard, or recently read, about unlocked phones. The newest offerings from names like HTC, Moto, and OnePlus are pushing the unlocked model forward each year by selling phones direct to customers. These “carrier-free” options are becoming more and more popular in the US, but what does it really mean? Allow us to attempt to help you understand this sector of the smartphone market with this Explained: What is an unlocked smartphone?

At its core, unlocked means one thing: the phone can be used on multiple carriers without any alterations. Essentially, you should be able to take a supported SIM card from a service provider and the phone should work. However, as with most tech, it’s not always so cut and dry. And especially in the United States, there are a few variables that come into play when researching unlocked smartphones.

The unlocked model is based on two main components: bands and radios. Both work together to recognize the carrier attached to your SIM card and then relays information back and forth via the supported bands. For example, 3 of the major carriers in the US support band 2. AT&T, Verizon, and T-Mobile use this band to support LTE communications. Chances are that if your new phone supports this band you could have some or all services available on these 3 networks. But did you notice I didn’t’ say Sprint? Well, this is where it gets kinda messy.



In our scenario, Sprint lacks the LTE bands 2 for the phone to work. Another thing to keep in mind when shopping for unlocked phones is that Verizon and Sprint are a rarity. This goes back to the radios mentioned earlier. American carriers are split amongst two different types of radio tech: GSM and CDMA. AT&T and T-Mobile are built around GSM while Verizon and Sprint are based on CDMA. This is a big deal because most of the world’s networks are also built on GSM and not CDMA. Therefore, manufacturers making “unlocked” phones will target the larger market of GSM based technology.

Let’s look at a brief example to better explain. The Moto G5 Plus and OnePlus 5 have both been released in the last few months. However, the OnePlus 5 doesn’t support Sprint or Verizon networks. It lacks the CDMA radio to function properly. In contrast, the Moto has dual GSM and CDMA radios providing full support for all four major carriers inside the United States and beyond. This is a trend that you will see play out across most unlocked phones with the OnePlus being the more prevalent example across them.

So what does this mean for you as a consumer? Personally, I love the movement towards carrier free purchasing, but I would stick to retailers that you can trust. Amazon does an outstanding job of breaking down the supported carriers for their phone sales. Unlocked phones are often a cheaper alternative to carrier exclusives, but just be aware that they are not all created equal. Honestly, I’d be a little hesitant altogether if you’re on Sprint or Verizon. I’d also recommend checking out sites like FrequencyCheck if you have further questions on a random device.