Smartphone Quick Tips: The Unlock

Unlocked CellphoneTwo years ago the decision was made by the Library of Congress to make unlocking cellphones illegal without the service provider’s permission.  This week a bill was signed into law that will allow consumers to more easily swap cell phone providers without needing to buy a new device. Although the law may be only temporary as the Library of Congress has a vote next year that may result in the reinstatement of the ban, let’s celebrate a little more cell phone freedom while we can.

So in honor of the Unlocking Consumer Choice and Wireless Competition Act let’s talk about unlocking cellphones.

To begin, a little background on the jargon.  A “locked” phone has software installed by the service provider that restricts the phone to use on their network.  For example, and AT&T locked phone will not work with T-Mobile’s service.  There are however certain phones that can be “unlocked”, allowing the owner to switch between networks and service providers.

How can you tell if a phone is unlockable?

First it has to be a GSM or SIM card phone.  In the US there are two types of cellular networks: GSM (Global System for Mobile Communication) and CDMA (Code Division Multiple Access).  GSM is the standard network used worldwide.  In the US there are four major cell phone carriers, AT&T and T-Mobile run on GSM networks, while Sprint and Verizon run on CDMA networks.  OK, so what?  What does this mean to the average consumer?  Well, while GSM providers attach your phone number to a SIM card, CDMA providers attach your number to the device itself.  In terms of unlocking: GSM phones can be unlocked, CDMA phones cannot.  Why, you ask?  To break unlocking down to its simplest form: an unlocked phone allows you to use a SIM card from any network.  Since CDMA phones do not use SIM cards they cannot be unlocked.  So no SIM slot equals no unlock.

SIM cards

But wait, my Verizon or Sprint phone has a SIM card, and you said CDMA phones don’t use SIMs and cannot be unlocked.  While there are custom software programs, hacks, and other methods of bypassing locks on CDMA phones with SIM cards, these phones were not intended for use on local GSM frequencies.  The SIM card slots in CDMA phones are either meant to run LTE data or to allow the phone to run on global frequencies – making the phone what is often referred to as global capable or a world phone.

Network frequencies vary around the world.  If you do find a way to bypass a CDMA phone’s locking software, do not expect it to function to its full capacity.  For example, you may be able to make a call but you will not have data service.  For the most part Sprint phones cannot be unlocked for use on local GSM networks.  There are some newer Verizon devices out there that come unlocked, but again this is intended for global use and may not function properly or to its full capabilities on the GSM networks in the United States.  On the reverse side CDMA carriers like Sprint and Verizon do not use SIM cards for their service.  No SIMs means no CDMA service on a GSM phone.  While you may find a CDMA phone that also supports GSM connection, you will never be able to operate CDMA service on a GSM phone.  So unlocked or not an AT&T or T-Mobile phone will never work with Sprint or Verizon’s service.

So now that we have a little background on locked vs. unlocked phones, let’s talk about how the unlocking process works

While there are programs that unlock phones through software manipulation, the most common unlocking process results in what is called a “factory unlock”.  A phone that has been factory unlocked remains unlocked even if the phone’s software is updated, customized, or restored to default.  This process require obtaining an unlock code direct from the phone’s service provider.

At Tech Armor, we send a request to the carrier on behalf of the customer.  If it is possible for the phone to be unlocked, the carrier responds with an unlock code.  The new SIM card is inserted into the phone and when powered on the phone will request the unlock code.  Once the code is entered the phone will run with any installed SIM.  If the phone uses data the internet settings must be adjusted in order for the phone to connect to the internet.  The APN (Access Point Name) must be changed.  The APN identifies which network the device should access for data use.  Once these steps are complete the phone will be up and running on its new network.

So now that you know basic what, why, and how of cell phone unlocking,

remember to head over to the experts at Tech Armor

for all you unlocking needs.


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  1. Andre Beluchi

    A cell phone with a lock/unlock feature does sound like a good feature to have. I was surprised that the the phone that was given to me didn’t have this feature. It seemed like somebody must have taken it out from the device. How can you bring that feature back into the phone?

  2. Kelli

    Greetings! I’ve been reading your weblog for a long time now and finally got the courage too go ahead and
    givve you a shout out from Austin Texas! Just wanted to msntion keep up the great job!

  3. bomb it 7

    Saved as a favorite, I really like your site!

  4. Wade Joel

    Unlocked cell phones are great. You can use any carrier you want. I had no idea estate you could use international SIM cards as well if you were traveling.

  5. Felix

    Aw, his was a very good post. Taking a few minutes and actual effort to make a very good article…
    but what caan I say… I put things off a whole lott and
    never seem to get nearly anythkng done.


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