A Sim Card, or Subscriber Identity Module Card, is a smart card that is in all GSM enabled mobile phones around the world and contains all the information you need to make and receive calls on a particular network. Most phone networks around the world operate on a GSM network, so that means if you already have a mobile phone in your home country - you can most likely use it abroad. Of course, when doing this you will be charged "roaming" charges, which are charges above and beyond your standard monthly charges and so traditionally it has not really been an option to take your mobile phone with you when you travel.
However, with the cost of technology decreasing all the time, its now a viable option to purchase a sim card for the country you are traveling to save on roaming costs, plus get a local number in that country.
Like with international phone cards, there are a number of providers in most countries that will offer a prepaid or post paid sim card which you can insert into your phone. The main providers across the globe include Vodafone, T-Moble, O2, Three and many more. Your best option is to find a third party that can provide you with the sim card as they often can offer extra incentives to buy from them - for example InternationalStudent.com offers a sim card for the USA.
To be able to use a sim card in your phone, you will first want to make sure you have compatible mobile phone. Most networks around the world use a GSM 900/1800Mhz bands, and the USA uses GSM 850/1900Mhz bands. The majority of modern mobile phones are now tri or quad band, which means they will be able to work on all networks, and unless you have a very old phone this should not be a problem.
You will also need to check that your phone is unlocked. Network providers sometimes lock your phone to their specific network, however you are fully entitled and allowed to unlock your phone. To check if you phone is locked, just get a friends sim card (who is one another network) and insert it into your phone. If it works then your phone is unlocked and can take any sim card, if it does not work then your phone is locked. The easiest way to unlock your phone is to contact your current provider and ask them for your phone unlock code - by law they have to give this to you, or simply visit phone unlocking for companies that offer this service.
Once you have completed these two checks - your current phone is ready for a new sim card!
Advantages of Sim Cards
- Cut Roaming - with a sim card you will no longer have roaming charges when you travel .
- Local Country Number - sim cards provide you with a local number in the country you are visiting.
- Keep Contacts in Phone - you can keep all your contacts in the phone so they are easy to access
- Easy Access - sim cards allows you to keep in touch with friends and family all the time, no matter where you are
Disadvantages of Sim Cards
- Need compatible unlocked phone - if you have an older phone it may not be compatible
- Expensive for people to call you - mobiles are not cheap to call, whether in country or for international calls to you.
- Network coverage - you are reliant on network coverage, which may be poor in some areas.
- Expensive - sim cards are not a cheap option, and calling credit can be used up very quickly.
Sim cards are a great option for those students that are planning to spend a long time in a specific country. As long as you have a compatible mobile phone, a sim card provides you with easy access for your friends and family to get hold of you plus a local number in your host country from the beginning which can help with your orientation and for registering for services like bank accounts. They can however become very expensive so you will need to closely monitor your spending on them, however if you couple a sim card with a good international calling card, you can also benefit from low cost international calls from your mobile phone.