Wireless 101: Unlocking My Phone

If you own an unlocked GSM phone it can generally be used on any GSM carrier. If you have an unlocked “world phone” and travel out of country you can use a prepaid SIM and avoid costly roaming fees. You may also be able to use your existing phone when switching carriers; this could save you money and possibly even help you avoid entering into a contract.

Using your phone on a different provider isn’t quite as easy as throwing another carrier’s SIM into your phone. While GSM technology is standardized- the bands that cell phone carriers own licenses to are not. Also if your phone is branded with the name of a service provider it is most likely “subsidy locked” to that carrier. So if you’re up for the challenge, read on to learn how to find out what bands your phone supports and how to get your device unlocked whether your carrier is ready to provide you with the code or not.


My phone is Locked?!?

More than likely- yes, it is. US carriers commonly SIM lock their phones so that the phone can only be activated on their network. The reason that they do this is because of the dominant business model of the wireless industry, phones are a loss leader. Even if you buy a phone at full price with no contract the carrier would lose money if you did not purchase any service with your phone. This is true for both postpaid and prepaid service. People could easily take advantage of this pricing model and buy a phone from one carrier just to activate on another, so SIM locking or “subsidy locking” is the commonly employed solution.

There is nothing wrong with unlocking your phone if you want to. Subsidy locks are not written into any US law and it’s not illegal to use a third party to unlock your phone. After the return period that phone is yours whether you stay or cancel or your carrier makes a profit or a loss on your account.

First Things First: Is My Phone Compatible?

While it’s easy to standardize the technology, standardizing the frequencies that companies broadcast on is next to impossible. There is a limited amount of spectrum shared by many different industries and every country regulates its own spectrum. A lot of the frequencies are common in many countries; some are pretty unusual and only used by a few carriers. Below is a chart that I made that shows what frequencies that different carriers and countries are using.

Your phone is also built to connect to a fixed number of frequencies so you have to match the supported frequencies of your phone to the network you want to use your phone on. You can look up what bands your phone supports on the manufacturer’s website or sites such as phonescoop.com.

Example of Dual Band GSM Phone:

Most mid to low end phones are typically “dual band” GSM and also “dual band” WCDMA. These phones will work in most North American countries. Older phones may be “single band” and only work on a few North American carriers. For maximum compatibility you would want a “quad band” GSM phone that is also “tri band” WCDMA. Most high end phones fit the bill. Carriers will sometime refer to these as “world phones.” A world phone supports all the major world frequencies and can be used in over 200 countries.

Example of a Quad Band GSM Phone:

The reason that carriers put the extra bands into their phones is not so you can unlock the phone and use it on another network. The bands are supported because your carrier has negotiated roaming agreements with foreign carriers so your phone can be used just by calling and asking for expanded roaming to be added to your plan. The foreign carrier charges your carrier a fee for roaming and your carrier charges it right back to you with a markup. Roaming rates in many countries are around $1.99 a minute. A Foreign SIM and a prepaid card from a foreign carrier will get you a lot more for your money.

If you’re looking up bands for an AT&T or T-mobile phone you’ll find that both companies intentionally exclude each other’s 3G band. Unlocked AT&T and T-mobile phones are still compatible on both networks but that compatibility is limited to 2G only.

Unlocking My Phone Through My Carrier:

Your carrier has some type of policy in place for providing an unlock code for certain phones. These policies used to be more restrictive in the US but because of a few lawsuits and pressure from the FCC unlock policies have become somewhat more relaxed. In other countries unlock policy may actually be written into regulatory law. Some countries bar SIM locking all together, others have well defined regulations for the length of service a customer must complete in order to be eligible to receive their phone’s unlock code.

Here is AT&T’s unlock policy as printed on their website:

To use an AT&T phone on another wireless network, you must unlock its SIM using an Unlock Code.

AT&T will provide the Unlock Code for phones on wireless plans if:

  • Your wireless service has been active for 90 days or longer
  • Your account is current and in good standing
  • Your phone is not sold exclusively by us
  • Your phone’s Unlock Code is available from the Manufacturer

AT&T will provide the Unlock Code for AT&T branded phones on Prepaid plans to customers who have either been on AT&T service for 6 months or longer, or provide a receipt or other proof of purchase.

Here is T-Mobile’s unlock policy as printed on their website:

SIM Unlock Code

For information on the SIM Unlock Code, refer to the following:

  • If you purchased a wireless phone from T-Mobile, your phone has been programmed with a SIM lock which will prevent the phone from operating with other compatible wireless telephone carrier’s services. If you wish to use the phone with the service of another wireless telephone carrier, you must enter a numeric SIM Unlock Code to unlock the phone.
  • For customers with a T-Mobile Postpaid Plan, T-Mobile will provide the SIM Unlock Code upon request to eligible customers, provided the requesting customer has a minimum of 40 days of active service with T-Mobile.
  • For customers with a T-Mobile Prepaid Plan, T-Mobile will provide the SIM Unlock Code upon request to eligible customers, provided the requesting customer has a minimum of 60 days of active service with T-Mobile and either a Prepaid Plan account balance of at least $10.00 or a prior refill within the last 30 days.
  • T-Mobile will provide the SIM Unlock Code upon request to eligible former customers, provided that T-Mobile has such code or can obtain it from the manufacturer.

Before you request your code you’ll want to get a SIM card from any company other than your own, even if it’s not the company you’re wanting to use your phone on. On virtually every phone the SIM unlocking dialog will only come up after you’ve put another carrier’s SIM into your phone.

When you do request the code ask if instructions on how to perform the unlock procedure can be e-mailed to you, otherwise the user’s manual for your phone will have instructions as well. The manual can typically be found on line if you have misplaced your own.

Entering in an unlock code can be frustrating and nerve-racking. Many phones have a sequence of 5 to 10 keys that must be pressed in order to even bring up the screen where you enter the code. The unlock codes themselves may have 10 or more numbers and to top it all off you have a limited amount of tries before the phone permanently locks to your carrier’s network.

My only advice on the matter would be to read the instructions carefully. If you don’t get it right on the first try, contact your carrier’s technical support or see if you can get help at a store.

When Diplomacy Fails: Unlocking Your Phone Through a 3rd Party

SIM locking is a legal grey area in the US. The right for carriers to lock phones is not written into any law or regulation. Likewise, creating a software application or product to unlock a phone or circumvent the lock is not illegal.

Ebay is where I commonly see these services offered. Buying a software application that unlocks many different phone models can be an expensive venture. Buying just your unlock code from someone who has authored one of these software applications costs next to nothing. Be careful if you see websites saying that you can download such applications from them for free. Some may be legit but many will just be computer viruses.

The reason that these programs work is because in many cases the unlock code is derived from applying a mathematical formula to a phone’s IMEI number. The IMEI is a 15 digit number that is unique to every phone, similar to a VIN number on a vehicle. Computer programmers can figure out what these formulas are and then write computer software that will generate the codes when an IMEI is entered.

Iphones use a software lock that can be circumvented by installing an unlocking app on the phone. As you may imagine this is not an app that you will find at the app store. Because this is an app that isn’t licensed by Apple, first you must apply a patch to the phone that allows unlicensed apps to be installed to the phone. This process is commonly called “jail breaking.” Again the software you need and instructions on how to complete the process can commonly be found on Ebay. Again you may find websites offering this for free but because of viruses this can be risky business.

The problem with unlocking the iphone is that if you update the phone it will be locked again. Apple intentionally disables the unlock patch with every update. So you can either stay up to date and continually patch your phone or just skip out on updating your phone. Also installing any unlicensed software onto the iphone voids the phones warranty.

Perhaps the easiest way to unlock a device without having to mess with any patches, complicated key sequences, and obtaining SIM cards is to use a Turbo SIM. A Turbo SIM is a very thin chip that presses over top of your SIM card. It is thin enough that the SIM and Turbo SIM will still fit in your SIM tray pressed together. The Turbo SIM will take the signal of another carrier’s SIM card and change it in such a way that your phone doesn’t realize it’s using another carriers SIM. These cards are available many places on the web. Installing the Turbo SIM may require trimming a small amount of plastic off of your SIM card to make it fit.

Front/Rear View of Turbo SIM:

The Other Option: Buying Unlocked in the First Place

If you’re looking for the freedom of being able to use your phone with whatever carrier you choose without having to go to any of this trouble, you can buy unlocked in the first place. Major online electronics retailers such as Newegg and Amazon sell unlocked phones. Usually they are sold on equipment manufacturers’ websites as well.

These phones are unlocked but they’re also unsubsidized so plan on spending a lot more money than you would spend on a contract phone for your carrier. You’ll still want to match bands; many of these phones are designed to work on a specific carrier even if the carrier doesn’t sell them. With a little searching you can even find phones that support WCDMA 1700/1900 that will work on both AT&T and T-Mobile’s 3G networks.

In Conclusion

GSM phones are generally compatible with other GSM networks. If you want to use your phone on another carriers network match the bands supported by your phone with the bands that carrier broadcasts on.

In order to do this you may have to unlock your phone first. You can do this by obtaining the unlock code from your carrier if available or from a 3rd party. Turbo SIMs can also be utilized to use your phone on another network without unlocking it. It is not illegal to use a 3rd party to unlock your phone.

Unlocking your phone can save your money in having to pay expensive international roaming charges and save you from having to purchase a phone when switching carriers.

The alternative to having to unlock your device is to buy unlocked in the first place. These phones are more expensive than contract phones but give you the freedom to use your phone with any carrier.

*Images courtesy of Phonescoop.com, Motorola.com and Ebay.com.

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