A large proportion of smartphone owners choose to save their contacts to the phone rather than their SIM card because SIM cards offer a limited space when it comes to the number of characters you can have in names, and the type of information that can be included, pictures for example.
However, if the phone needs to be restored to factory default, you'll lose all your contact information. This is where copying your contact to a SIM card comes in. At least then you'll have a record of all the names and numbers you need. Here's how to do it on a BlackBerry. However, it is worth noting you can only save one contact to the SIM card at a time, so this will be a time-consuming activity.
From the Home screen, select Contacts
Select the contact you want to copy to your SIM card and then press the menu button
Select Copy to SIM phone book. You'll be given the chance to edit the name, phone number and email address if you need to.
Press the Menu key and then select Save. Your contact will now be saved to your SIM card.