“World Phone” Compatible
This is a big one. Some phones simply won’t work in a lot of the world. Chances are pretty good your newer smartphone will meet this requirement, with one very large exception, if you are a United States resident that and you don’t use AT&T, you might be out of luck. AT&T, and most of the world use the Global System for Mobile Communications or GSM standard and operate on one or more of the following frequencies:
2G (Voice, SMS, Data): 850, 900, 1800, 1900 MHz
3G (Data): 850, 900, 1900, 2100 MHz
Phones that are compatible with these frequencies are what we consider “World Phone Compatible”. You will see it noted simply as “World Phone Compatible” or GSM 850/900/1800/1900/2100 throughout the site. You can probably get away without the 1800MHz compatibility most places, but if your phone supports the other standard GSM frequencies it will likely support 1800 MHz regardless.
You will want to bring a GSM phone that has these specifications. Generally if there is only one version of a phone made, it will one with these specifications. If you are with AT&T in the United States, one of the big three in Canada (Rogers, Telus, Bell and subsidiaries) and most major European/UK carriers your phone will be good to go in most of the world (as long as it is unlocked), and you can stop reading here.
Take a look at our What Kind of Phone? article for further information on choosing a phone for travelling.
Phones from other Carriers and LTE
If you have a T-mobile compatible phone in the USA, or a WIND or Mobilicity compatible phone in Canada, you will be able to use it in most of the rest of the world for voice, SMS and 2g (very slow) data but you will not be able to connect to 3G networks. We would not recommend bringing it with you, as 3G data is very useful. 2G can be painfully slow, sometimes to the point of not being usable for even the simplest of tasks. That said, some newer phones operating with these carriers will contain the extra radios to make 3G connections possible in the rest of the world, you’ll have to check your specific phone for the frequencies noted above.
And, Verizon. Oh Verizon. Verizon is one of the last (the last?) companies in the world to use the CDMA standard (instead of GSM). Weird that there would be a standard that still hangs on only in the US…right, no, not weird at all. Older Verizon phones don’t even have a sim card slot, and do not use GSM frequencies so using them on carriers in the rest of the world is not an option. Some newer Verizon phones do have a sim card slot that will contain a “roaming sim” that allows usage in the rest of the world (at high roaming rates). But, if your newer Verizon phone is unlocked, and contains this “roaming sim” it may be possible to swap it out with a foreign sim card.
LTE networks are another animal altogether with frequencies varying carrier by carrier and country by country all over the world (the parts of the world that even have LTE). We don’t recommend worrying about it unless you really need the speed, and in that case research the specific country, and carriers, before hand. On the standard 3G frequencies listed above, speeds up to HSPA+ are possible, and usually more than sufficient. Don’t tell your North American carrier we said that (really guys, up data caps first, upgrade your network speeds later). You can find a list here (that may or may not be up to date) of frequencies used around the world.