For most mobile phones and smartphones:

1. Carefully push the SIM card out of the wallet-sized plastic card carrier.
2. Turn your phone off.
3. Remove the back panel of your phone and the battery. You'll see a SIM card slot.
4. Your SIM card has one corner missing. Fit the SIM card into the slot so that the corners match.
5. Replace the battery and battery cover.

For an iPhone:

1. Insert the end of the SIM eject tool (included in box) into the hole in the SIM tray.

   Tip: If you don't have a SIM eject tool, you can use the end of a paper clip.

2. Press firmly and push the eject tool straight in until the tray pops out.
3. Pull out the SIM tray and place the SIM card in it, following the shape of the tray.
4. Carefully push the SIM tray containing the SIM card back into the iPhone.