By law, all cellphones sold by an authorized dealer in Costa Rica are unlocked GSM phones that meet Costa Rica’s frequency standards. If you are bringing a phone to Costa Rica, it must meet the same requirements.

A locked phone is simply one that is locked to a single cellphone carrier. Locking cellphones is a standard practice for USA carriers, who sell phones at a discounted rate as part of a contract, usually two-years. The unlock code is not the SIM pin code, or the Lock Passcode, which are used to protect against unauthorized access to your cellphone. The unlock code releases the phone from being tied to a single carrier.

Unlocking a GSM phone requires that you know the IMEI (International Mobile Equipment Identity) number of the phone. This is a unique number assigned to every GSM mobile device. Essentially, it is the serial number of the device, and cannot easily be changed. On most phones, you can retrieve the IMEI number by dialing *#06#. If this doesn’t work, you can try ATD*#06#. On older Sony or Sony Ericsson phone, you will need to press *Right*LeftLeft*Left*. On some phones, you can find the IMEI number under the phone settings. As a final resort, you can find the IMEI number on a label under the phone battery. While you have the battery removed, you might also want to take note of the phone model number. Write the IMEI number down, as you are going to need it several times throughout the unlocking process.

Before unlocking your phone, you need to be sure that the phone meets the GSM frequency requirements for Costa Rica. Not all GSM phones support these requirements. You check if the phone was certified by SUTEL. Finding your phone on this list means that the phone is certified to work in Costa Rica. Non-certified phones that meet the frequency requirements still should work. If you have the manual for your phone, you can check the specifications to see if the phone meets the requirements. If you don’t have the manual, you may be able to get it from your previous carrier’s Web site. You can also check the specifications for your phone at Phone Arena or GSM Arena. There are a lot of phones on these sites, and it really helps to know the model number, and not just the marketing name of the phone. For example, the Samsung Galaxy S II is the generic name for the phone, but there are twelve different models of the phone. If you are not sure of your exact phone model, you can try to retrieve the phone information from IMEI Number Lookup.

Once you know that your phone meets the frequency requirements for Costa Rica, you are now ready to find the unlock code. In general, contacting your previous carrier is a fruitless exercise, especially if your phone is still under contract. StraightTalk phones are an exception, just be prepared for a long phone call. They take you through a number of security checks to make sure that the phone is not a stolen. The fastest way to get an unlock code is from one of the many Web sites that supply them.

A general warning!! You can only enter a lock code four times, before the phone is really locked. If this happens, you will be forced to call the previous carrier to get master security code that unlocks the lock code entry feature. I have only made this mistake once, and it is a real pain getting the master security code.

For older phones, you can usually find a free unlock code. The lock code for these phones are based on either the DC3 or DC4 algorithm using the IMEI number. Unlockeitfree.com is a good source for older Nokia phones. They even provide an option for generating the master security code. The site will generate seven unlock codes. Following the instructions, enter the first unlock code. If it fails, try the last unlock code. On rare occasions, you may need to try one or two other unlock codes. Trycktil is a Swedish site that provides unlock codes for certain models of Nokia, LG, Panasonic, Siemens, Vitel, and Maxon phones. While their Web site is not the easiest to navigate, Free Cell Phone Unlock provides unlock codes for select models of Blackberry, iPhone, HTC, LG, Motorola, Nokia, Sony Ericsson, and Sumsung phones.

For newer phones, the chances of finding a free unlock code is very slim. The algorithms for calculating the unlock code have changed. Some phone manufactures only provide the unlock code to authorized providers. Some phones require multiple unlock codes. Code Unlock and Unlock It Now provide unlock codes for a wide variety of phones. While Unlock it Now covers more phones that Code Unlocked, Code Unlocked has a lower price for the phones that it does cover. The unlock codes can cost as little as $4.99 USD.

Some Nokia phones use a BB5 lock code that cannot be generated by any service. The BB5 lock code only applies to specific carriers. For example, the Nokia E71 from StraightTalk uses a BB5 lock code, but the same phone from other carriers does not. Some European carriers also use the BB5 lock code on Nokia phones. Unlocking these phones requires special software that is beyond the scope of this article.

With the unlock code and instructions provided, you are ready to unlock your phone. For most phones, there are just a few steps to unlocking your phone. If you carefully follow the instructions, you should be able to unlock your phone without any problems. Some Sony and Sony Ericsson phones do require that you tether your phone to your PC to execute the instructions. Normally, you just need to enter the codes given in the instructions. Once unlocked, you should be able to activate the phone with your Costa Rica SIM card.

Many cellphone stores provide an unlocking service. Except for Nokia’s BB5 unlock code, it really is just a matter of generating an unlock code and then executing a few steps to unlock the phone. For this service, they usually charge 25,000 to 30,000 colones. I have found that they do not know how to unlock a Nokia phone that requires a BB5 unlock code. If the person unlocking your phone mentions that the phone requires a “software change,” you need to ask exactly what kind of change. Unlocking a phone does not require a software change. Changing versions of software on an Android phone, usually means installing another version of Android, such as CyanogenMod. While CM7 (Gingerbread) works fine on my tablet, it may not work on every phone. I would suggest that you do the research mentioned above, before taking your phone to anyone to have it unlocked.

If your cell phone is under contract, the contract may prohibit unlocking the phone. AT&T and iPhone contracts normally contain such a clause. Even though your contract payments are current, they may lock your phone, after you unlock it. If this happens, you will to contact them to unlock your phone.

One final comment about the IMEI number. You should keep this number in a safe place. If your phone is stolen or lost, you need to report it to the police using the IMEI number as the serial number. Then take the police report to the carrier providing your phone service (ICE/Kolbi, Claro, or Movistar) and report the loss. Per an agreement reached with SUTEL, the carrier will “blacklist” the phone. A phone on the “blacklist” cannot be activated by any carrier in Costa Rica, or any country that supports reporting stolen phones to the Central Equipment Identity Register (CEIR) the “blacklist”.