This is a simple guide that explains what it means if your cell phone is unlocked and, how you can tell if it is, as well as some suggestions on how to get your phone unlocked. Simply put, if your cell phone is unlocked it can be used with more than one wireless carrier like T Mobile and Cingular. For a more detailed explanation read on. If you find this guide helpful, please help others find it by clicking the "Yes" in the blue title bar below.
I will start with what is means to be locked. Many years ago, the wireless carriers such as AT&T and others started a marketing strategy of paying for some of or all of the cost of a new cell phone if the customer would commit to a one or two year contract to use their wireless service. The wireless carriers did not want to pay for the phone and later have it used with another carrier, so they got the cell phone manufactures to design the phone to be locked to just their service. For example, if AT&T paid for the phone, AT&T would lock it so that it could only be used on AT&T and not T Mobile. This lock is called by several names including "Sub Lock" or "SPC Lock" or "Sim Lock".
Now that you know why the cell phones are locked, I will discuss how to tell if your phone is locked or unlocked. First, you must determine if your phone is a GSM phone or a CDMA phone. This is easy to tell, if the phone uses a sim card (a small piece of plastic that you put in the phone, see picture below), it is GSM, if it doesn't, it is CDMA. The US carriers that are GSM are Cingular and T Mobile. The CDMA carriers are Verizon, US Cellular, Alltel, Qwest, and Sprint PCS. Both CDMA and GSM phones are generally locked, however, only unlocked GSM phones can be easily switched from one carrier to another. I will address each seperately.
Sim Card Sim Card Inserted
GSM Carriers (Cingular and T Mobile are the biggest two). When a GSM phone is unlocked, it will work with any active sim card. So you can put an active T Mobile card or and active Cingular card and the phone will make a call. Now some features of the phone may not work, like the internet browser if the phone is not programmed to the particular carrier, nevertheless, you can make calls.
CDMA is a little different. The cell phone does not use a small sim card and the phone must be programmed to another carrier to work which generally requires that the phone be hooked to a computer that has special service software to program the phone. If you don't have the software, and it is not readily available, CDMA phones are, for all practical purposes, locked to the carrier they are programmed to.
How can I unlock my cell phone? You can find companies that unlock cell phones on eBay and on the internet. Some companies are able to unlock the phones remotely, meaning if you send them the imei number on the phone, they send you a code to unlock the phone, others require you to send them the phone. Each model is different, so you will have to search a little. Charges range from $5.00 to $20.00 depending on the model of the phone and which company you go to.
If you are purchasing a phone on eBay, look for one that is already unlocked. I hope you found this guide helpful, if so, please click yes below. Also, check out all the phones that I offer on eBay, I can unlock almost every phone made and I generally unlock them before I sell them. If you want to learn even more about unlocking see my guide "After Unlocked Cell Phones: What it Means to be Unlocked". Thanks for reading.