[header] How to use a sim card to switch phones [title] Open the contacts list on your original phone. [step] It's possible to back up your contacts to your sim card before transferring it, but this isn't always the most convenient option. It's useful if you're moving to a dumb phone, but if you're using smartphones your contacts are typically synced with your google account or apple id. 
[title] Open the menu and select " export " or similar option. [title] Select your sim card as the destination for the exported contacts.