What are Unlocked Phones? A Super Guide

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What you hear that a mobile/wireless carrier sells unlocked phones, what does that mean? In simple terms, an unlocked phone is a mobile device that is not tied or locked to one specific carrier. 

Many years ago in the United States of America, cell phones were sold strictly carrier locked. You go to your cell phone company and pick from whatever phones they had available. Yes; you were able to get the phones on a payment plan, but it was limiting. It still is.

Which is why, if you want the freedom to pick and use a smartphone of your choice, the way to go is to buy your cell phone unlocked.

unlocked phones

What is a carrier phone?

A carrier phone (or locked phone) is sold through cell phone carriers, or through 3rd parties like Best Buy and Walmart. Carrier locked phones are purchased from a mobile carrier and are locked to that specific carrier. If you want to use such a phone on another carrier, you need to pay the balance on your contract and then have it unlocked.

Carrier phones come with a SIM card and/or line, as well as require a service signup. As a matter of fact, in many cases, you cannot switch your number from one phone to another without the involvement of your carrier and a service charge.

Carrier phones sold through 3rd party partners are called Universal or SIM Out devices. Unlike locked phones, they are initially unlocked and you can use them on any carrier of your choice, BUT they immediatly become locked to that first carrier. To use them on another carrier or network, you need to have them unlocked too.

Unlocking a smartphone can be tedious and frustrating, depending on the carrier’s terms and conditions.

What is a carrier locked phone?

A carrier locked phone (or simply a locked phone) is one that is purchased from a mobile carrier and is “locked” to that carrier, such that it cannot be used on another carrier. For example, if a smartphone is locked to Verizon, it cannot be used on T-Mobile or other carriers.

To use a locked phone on another carrier, it has to be freed up by a process called “unlocking”. Now, let’s explore what unlocked phones are and how they work.

USA phone numbers and cell phone carriers - four national Mobile Carriers Verizon att sprint tmobile

What are unlocked phones?

Factory unlocked cell phones are devices that are not purchased from any carrier or 3rd party partner and are also not locked to any carrier, regardless of what carrier you use them on first. They come with no SIM card and no signup requirements.

When you buy an unlocked smartphone, you can freely use it with SIM cards from any compatible carrier without worry.

Are prepaid phones unlocked?

Not necessarily. You can buy a prepaid phone unlocked or locked, depending on whether you source it from a carrier or an independent retailer. For example, you can buy a prepaid cell phone from a 3rd party partner, put a SIM card from a carrier into it, and it becomes automatically locked to that carrier.

However, carriers are required to unlock your within 12 months after initial activation. Sometimes, you can get it unlocked within a much shorter time.

Benefits of buying a carrier phone

When you buy a carrier locked phone, you get to pay the total cost of the device in monthly instalments. Also, many times, carriers offer these phones at discounted prices for the trade-off of being locked in with them. So you will liley get both lower cost and convenience with payment if you opt to buy a smartphone from your carrier.

Lastly, you are sure that the phone in question works with your carrier, because such phones have been tested and configured by the carrier before making them available to the public.

lg zone 4 prepaid phone verizon

Benefits of factory unlocked cell phones

The number one benfit is freedom – the freedom to use SIM cards from any other compatible carrier in your phone. The freedom to switch your number whenever you want. The freedom to use your smartphone and number how you want without any restrictions from a carrier.

Also, because carrier phones often come with pre-installed apps from the carrier, embracing unlocked phones means you have less bloatware on your smartphones.

Note that, sometimes, carrier phones are more expensive than unlocked ones, because often, carriers hide certain costs in the total bill. So, buying an unlocked phone could also mean paying less in some instances.

What Happens When You Activate an Unlocked Phone on Your Carrier?

What does it mean to activate an unlocked phone? The answer requires a bit of history. Back in the old days of CDMA networks which did not use SIM cards, activating a cell phone meant making the phone active on a carrier network. Because the mobile number has to be baked into the phone, activation was the procedure that linked a specific cell phone to a specific customer account and phone number.

Fast forward to the twenty-first century when CDMA networks are gone and we all use GSM phones that require SIM cards, cell phones aren’t activated. It is the SIM card that has to be activated so that it can register with the network when it is inserted into a phone and the phone is switched on.

You can activate an Unlocked phone on your carrier
Apple iPhone 8 Plus GSM Unlocked 64GB – Space Gray

Americans still loosely talk about activating a phone, but in reality, it is the SIM card that has to be activated. If you have an already activated SIM card, you can put it into your unlocked cell phone right away at the point of purchase without any activation process required with your carrier.

Strictly speaking, when you activate an unlocked phone on your carrier, it is the SIM card that is activated (if new), not the device. If you have an already active SIM card, just put it into your new unlocked phone, power it on, and start using it.

If you activate an unlocked phone on your carrier, does the phone become locked?

Not at all. If you purchased an unlocked phone, it remains unlocked on whatever carrier you use it. A carrier cannot remotely lock it, nor would they be allowed to do so.

Carrier network locked phones are phones that the carrier has modified and made available to subscribers, usually at a discounted price through a contract to keep those subscribers on their network. Hence the network lock. A phone that is locked to Carrier A can only be used on that carrier. If you put a SIM card from any other carrier in it, the phone will be unable to connect to their network. That is why it is called a network locked phone.

Once you have paid off your contract, you can request your carrier to unlock the phone, and they will do so. The phone becomes unlocked, freeing it for use on any other carrier.

Can you activate a phone without a SIM card?

As already explained at the beginning of this article, cell phones aren’t activated. It is the SIM card that has to be activated so that it can register with the network when it is in a phone and the phone is switched on.

Activation of the SIM involves associating the SIM card ID number with a specific cell phone number and account. If the SIM is moved to another unlocked phone then the account and cell phone number will move to that second phone.

An activated SIM card can be used in any compatible unlocked phone. An unactivated SIM card is a dud – completely useless.

A SIM can be used in a locked phone if the phone is locked to the same network that issued the SIM card. If the phone is locked to a different network from the SIM card’s carrier, the SIM card is useless inside that phone.

If you are buying an iPhone, you will likely be interested in finding out the different kinds of unlocking available for iPhones.

Why Your Unlocked Phone Will Not Work All Over The world Or On Every Carrier

Now and then, I run into someone who is complaining that an unlocked phone they purchased in one country does not work when they travelled or migrated to another country. Usually, the complainant blames the phone, when in reality there is nothing wrong with it. Here’s an example of such a complaint:

The phone worked well in Nigeria, but had limited use while I was in Cairo. Now in the US, the phone DOES NOT WORK! HOW CAN THAT BE??? Why would an unlocked phone no work all over the world???

Different Countries; Different Frequencies

Different countries use different mobile frequencies for GSM, 3G, 4G, and 5G services. One country may use a particular frequency that another country does not use. Among other reasons, this is why each country’s regulatory authorities have to approve devices for sale in their countries.

That a phone is not locked to one network does not mean it is compatible with all networks everywhere. This is because different countries adopt different frequencies for their telecommunications services.

Your unlocked phone will not work in every country because phones support different frequencies

You will hardly ever find one smartphone that supports all GSM frequencies used in all countries around the world. For example, with GSM alone, there are 14 GSM frequency bands or cellular frequencies designated by the ITU for the operation of GSM mobile phones. There are even more frequencies for 3G and much more for 4G.

The big smartphone manufacturers are able to support more frequencies than smaller brands are. Even then, they are unable to support ALL frequencies in one phone. In some cases, to cover all countries, the manufacturer makes two or more variants of the same phone. Variant A will work in some countries but not in some others. Variant b will work in countries not supported by Variant A.

PS: When next you complain about the higher cost of the bigger brands, this is one of the reasons behind it: their devices are compatible with a wider range of frequencies than devices by the smaller, often cheaper brands. Here is a breakdown of the kind of differences to expect:

  • GSM: The average budget smartphone brand supports 2 GSM frequencies (900 and 1800) while bigger brands support up to 4.
  • 3G UMTS/WCDMA: The average budget smartphone brand supports 2 3G frequencies while bigger brands support up to 5.
  • 4G LTE: The average budget smartphone brand supports 3 to 4 4G LTE frequencies while bigger brands may support up to 20.

An Example

For example, in the United States of America, GSM operates on the primary mobile communication bands 850 MHz and 1900 MHz. In Nigeria, the supported GSM frequencies are 900 MHz and 1800 MHz. See the difference? The implication is that an unlocked phone that supports only bands 900 and 1800 will be usable in Nigeria but useless in the US.

Imagine buying a certain unlocked smartphone that supports only GSM 900 and 1800 MHz frequencies, which are not used by mobile networks in the USA. As such, the phone worked in Nigeria but not in the USA.

Your Unlocked Phone Won’t Work On All Carriers Either

In the United States, Verizon uses a different set of frequencies from T-Mobile. As such, unless an unlocked phone supports both their networks, it will work only on one and not on the other. This is different from a case where a phone is locked to one carrier.

Your Responsibility, As A Consumer

If you do a lot of travelling, familiarize yourself with the wireless frequencies that those countries’ mobile networks use. Then, do your research before you buy a smartphone so that you end up with a smartphone that supports those frequencies. Or buy a backup smartphone that supports them. This is also valid if you want to switch between carriers in the United States.

Read up specifications sheets about phones you are interested in. Here is what to look for when you read a specifications sheet on MobilityArena:

gsm 3g 4g frequencies

In the above image, the red arrow points to the GSM frequencies that the phone supports. The blue spells out 3G (UMTS/WCDMA) frequencies, while the green arrow spells out the 4G frequencies. With the arrival of 5G technology, the same principle applies. There are different frequencies adopted by different countries, and your 5G phone has to support the ones used in the country you are visiting for you to enjoy 5G service there.

Now you know what to look out for in order to make informed choices about what mobile phones to buy if you travel from country to country on a regular basis. Do not forget: buying an unlocked phone does not mean that it will work all over the world or on all carriers.

How to buy an unlocked phone

If you want to purchase an unlocked phone, your best bet is to buy from the manufacturer. Walk into a physical store e.g. Apple Store or Samsung Store to buy your phone. Alternatively, you can also buy one directly from the manufacturer’s website. There are also independent 3rd party stores and e-commerce sites that sell factory unlocked cell phones.

If you want an unlocked phone, do not go to a carrier store or a 3rd party partner store. Don’t forget that you are paying the full cost of the phone upfront too.

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