What's the Best Way to Go, Unlocked or Locked?
The short answer is it depends. The long answer depends on your finances.
Locked phones give you a lower entry point, but you end up paying more for the phone and the data plan in the end, so ultimately, you're paying a larger total cost of ownership. To mitigate the significant cost of buying the phone at full or nearly full price, you can use pay-as-you-go plans with an unlocked phone, and those can be as low as $50 a month for unlimited voice, text and data.
Americans are used to the lower initial cost and have become dependent upon the instant gratification that comes with reduced purchase prices for high-end phones. In contrast, the European Union has mandated that unlocked devices be made available to its citizens, albeit, at full retail price. As a result, many Europeans purchase an unlocked phone, and are usually able to select the mobile communications plan of their choice, both with, but most usually without a set contract term.
Unlock or Buy Unlocked First?
In our opinion, buying an unlocked phone is the best option. It ensures the smallest total cost of ownership over the life of the phone.
Jailbreaking and carrier unlocking anything but an iPhone by yourself is risky. iPhones have well known, tested hacking tools that make it easy to jailbreak the device, which is the first step in the manual unlocking process. The next step, manually removing the carrier lock, is what is now outlawed. It's also very risky if you don't know what you're doing, or if you don't legally request or purchase an unlock code.
You can request an unlock code from the carrier. In general, after your contract is older than 60-90 days, and you can provide documented proof that you're going to travel internationally, carriers may allow you to call them and request an unlock code for the phone. This doesn't exempt you from your contract, or void the ETF should you break the contract, but it will allow you to use the phone on a competing network when you travel.
You can also simply purchase an unlocked phone and then either purchase a pay-as-you-go voice and data plan or a compatible voice and data plan from a major carrier. The device will cost you more, but you're free to buy the rate plan of your choice and that, over time will likely save you the difference in the cost of the device and more. The point is you have the freedom of choice. As long as your rate plan doesn't lock you into a set contract term, you can purchase the service and price point you want at your discretion.
Which phones and carriers are best
Which phone and carrier is best for you is going to depend on which carriers are available and have the best service in your market. We've seen it vary from city to city, state to state, so look around, ask your friends, etc.
Assuming the device in question uses the communication frequencies of the target network, GSM phones are easiest to unlock and move from carrier to carrier thanks to their SIM card slots. "I've bounced a single device between AT&T and T-Mobile here in the states as often as I've needed simply by swapping out SIM cards," notes Contributing Editor Chris Spera.
The phones and carriers we don't like
There is also no one answer for this. It will also depend on carrier availability and quality in your intended market. In the U.S., unlocked phones on Verizon and Sprint don't make a lot of sense. Activating devices on their CDMA networks is more complicated and often involves the carrier due to their lack of a SIM card slot. However, should you want to use Verizon as a carrier and plan on doing international traveling and you own an iPhone that runs on their network, you're in luck. Apple and Verizon unlocked the SIM slot in the iPhone 4S and iPhone 5. Verizon's CDMA radio has never been locked in its branded phones.
The SIM card in the Sprint iPhone 4S/5 is locked. Click here for Sprint's guidelines for unlocking.