If the screen of your mobile is displaying either of the messages “Insert SIM", "SIM error" or "SIM card rejected", try the following:
Check that the SIM card is inserted properly and the right way round
Wipe the SIM card with a non abrasive material and re-insert
Try another battery in your mobile
Try another SIM card to see if the problem lies with your SIM card
Try your SIM in another mobile to see if the problem lies with your mobile
If an incorrect PIN has been entered on your mobile handset three times, you’re given 10 attempts to enter a correct PUK (Personal Unblocking Key). If an incorrect PUK code is entered after the 10th attempt, your SIM will become permanently blocked and you’ll require a new SIM card. Click here if you need to obtain a replacement SIM card or if none of the above assists.
