There are several important guidelines that you need to know before you choose to use a cell phone abroad. First you have to know whether your current cell phone will work, or if you will have to rent one.
Whether your own phone will work will depend on if it GSM or CDMA capable. These are simply the names of the types of networks used by different carriers and different countries. The major difference is that a GSM tower relays calls faster, and a CDMA tower relays a higher volume of calls. In the U.S., Verizon and Sprint use CDMA technology while AT&T uses CDMA technology.
Some phones are what is known as dual capable, meaning they can either operate on a GSM or CDMA bandwidth. Depending on your type of phone, it will usually have to have feature activated on it that allows it to make international calls. Others need additional hardware like a SIM card, or a different package. The Blackberry phone, for example, must be on a different data package to allow for free data use in a foreign country. Other dual band capable phones will just need something like an “International Dial” feature to allow the phone to work. Usually you have to contact customer service to activate the feature, since it is a billing as well as phone feature, but in some cases you may be able to activate the necessary feature online. It wouldn’t hurt to call a customer service representative just to make sure. They will also be able to give you dialing instructions, rates, and any additional steps you may need to take with your phone upon departing and arriving.
Your phone only needs to be both GSM and CDMA capable if you are going from a CDMA network at home to a GSM network oversees. The British Isles, for example, operate solely on GSM technology. If your phone isn’t capable of receiving these signals, you will either need to rent one or buy one. Some phone companies have a global rental program when you can lease a phone just for the duration of your trip.
An entirely different option is to purchase a pre-paid phone once you arrive at your destination. Prepaid phones and refillable minutes vary in price according to location. When I traveled in Mexico, I would have been charged $.50 a minute and a lot to text to use my American phone, but I found a pre-paid phone for the equivalent of $40 US dollars, with only .$10, plus free text messages. Since I was there for several months, this option worked out cheaper.
Before you think about how you will communicate when you travel abroad, it is important to call or research to rates for voice minutes, text messaging, and data, and decide which services you need. I have heard of cases where travelers racked up hundreds or even thousands of dollars worth of charges just because they did not understand all the different rates. Calculate the cost of the minutes, the cost of a phone that has to be bought or rented, and make a budget of how much you can talk or text. This way you can be in control of your phone’s use, and not be surprised by the next monthly statement.