You can copy contacts between your SIM and phone. This way, you won't lose your contacts if you change your SIM or phone.
Slide your finger right starting from the left side of the screen.
Press Import from SIM card.
Press the drop down list.
Press Locally saved contacts.
Press Export to SIM card.
Press the menu icon.
Press Mark all.
If you want to keep existing contacts saved on your SIM, press Add contacts.
If you want to replace existing contacts saved on your SIM, press Replace all contacts.
Press the Home key to return to the home screen.