SIM stands for ‘Subscriber identity module. A mobile sim card is basically a small chip that can be easily transferred from one phone to another and holds lots of information about the phone and your calling plan.

It has to be activated by the use of a unique number and when this is done the sim card is then locked to that network.

It is used to hold all your contacts, the mobile phone number, text messages and lots more data used by you. It is very easy to transfer a mobile sim card from one device to another and could be very useful if your phone ran out of credit, you could put your sim card into a friends mobile phone and use it just as if it was your phone. This would not count towards your friends call time as the debit would be on your call time.

If you decide to change your phone this is a very simple procedure and you can just slide the sim out of the old phone and into the new one and ‘voila’ your new phone is active with all you info intact providing the other phone is on the same network.

When travelling you are able to purchase a mobile sim card for the country you are visiting, which saves such a lot of the charges, incurred when using a mobile phone abroad.