Using Your Cellphone While Traveling
The following is a summary of various options you have for using your cellphone while outside of your home country. The information is written for people travelling with US cellphones; however, it generally applies to cellphones from other countries as well.
Option 1 – Using WIFI (free option if in a free WIFI zone)
If you wish to use the data services on your cellphone without getting charged by your carrier, it is advised to leave your cellphone in airplane mode while travelling and just turn on the WIFI to use while you are in a WIFI zone (such as in your hotel or at a café) or turn off data roaming on your cellphone if it has that option. It data roaming is not turned off or your phone is not in airplane mode, data charges may incur even if you are in a WIFI zone.
If you wish to make phone calls, you can use an app such as Skype over WIFI and pay the low per-minute price that Skype charges to call any country around the globe.
Option 2 – Roaming (easiest option)
The easiest way of having full use of your cellphone while traveling is by roaming. In order to use roaming on your cellphone you will need to know two things. The first is if your cellphone is GSM compatible. AT&T and T-Mobile use GSM, while Sprint and Verizon use CDMA. If your phone is GSM compatible (uses SIM chip technology), it most likely will work throughout South & Central America with roaming. Also, one should note that CDMA carriers, such as Sprint and Verizon, have made most of their phones GSM compatible.
Second, you need a cellphone plan with a carrier that has roaming agreements in South & Central America. All the major US carriers (AT&T, T-Mobile, Sprint, and Verizon) have roaming agreements throughout the region. You can visit the carrier´s website or call them to find out if they have roaming agreements with the country you are visiting and how much the roaming rates are (they normally vary country to country). It can be quite expensive for making calls and using data. SMS text messaging is generally the cheapest feature you can use while traveling.
If you just would like to know when someone is calling you or make phone calls, the most economical way would be to leave your cellphone on and turn off data while roaming (or restrict data usage to WIFI only). If you allow your phone to roam with data, you may incur very heavy charges as cellphones use data when they are turned on, even if you are not using the cellphone. This way you can make and receive phone calls at a per-minute charge (check with your carrier for the rate) and then use the data on your phone (to check emails, use apps) while in a WIFI hotspot.
If you wish to use data anywhere while travelling, you may want to prepay for a set amount of data. This is generally cheaper than arriving and paying for data as you use it. Please contact your carrier to see if this option is available with your plan.
Option 3 – Purchase a local SIM (most economical option for having full use of your phone)
GSM phones (or dual mode phones that have GSM capability) use a SIM card that identifies the phone and account. This allows you to switch out the SIM card for a local country’s SIM that you purchase in that country. The caveat to this is that your phone must be unlocked. Most phones purchased in the US through a carrier are locked so that they only work on that carrier. If you purchased your phone outright at its full retail price, it is most likely already unlocked. Even if your phone is locked, most carriers will unlock your phone for use in other countries if you ask them or it may even already be unlocked for international use. Please check with your carrier to see if your cellphone is already unlocked or if they can unlock it for your trip.
Assuming that you have an unlocked phone that is GSM compatible, then you can purchase a SIM card in the country you are travelling to. That said, you need to ensure that you are purchasing the correct size SIM card (nano, micro, full size, etc.) for your phone and it is recommended to purchase a SIM that already has money on it and activate the SIM in the store or kiosk where you purchase it. If you need to add more money to your prepaid SIM you will need to find a store that is able to do so (there could be a language barrier, but most grocery and convenience stores allow you to add money). Adding money online doesn´t work in most countries since oftentimes the carriers in the foreign countries often don´t allow foreign credit cards to add money to a prepaid SIM chip.
When you use a SIM chip from another country, your cellphone number will change to a local number in that country. At the end of your trip, when you put your original SIM chip back in (or remove the local SIM chip if you are using a dual mode phone), your phone will return to its previous phone number.